• Impact of high-intensity interval and continuous aerobic training on left ventricular mass and circulating cardiac troponin T
      -
    • Increased resting cTnT level induced by exercise training is independent of any changes in left ventricular mass
      -
    • Exercise training increases resting circulating cardiac troponin T independent of change in left ventricular mass
      A Randomized Controlled Trial

    Therefore, we hypothesized
    (1) that among sedentary obese females, HIAT and CAT would result in an increase in resting cTnT, compared to pre-training levels,
    (2) the increase of resting cTnT would be greater after HIAT than in CAT, and
    (3) the larger increase in cTnT after HIAT would be associated with a more pronounced increase in left ventricular mass.

  • Title: Statement of your core result or finding.

    Try to make your title an assertive statement, such as:

    • “Changes in cytoplasmic volume are sufficient to drive spindle scaling.”

    and not

    • “High-performance silicon photoanodes passivated with ultrathin nickel films for water oxidation”

    Rule of thumb: if your title would look weird with a period at the end, it is probably a poor title.

    Don’t do this.

  • Abstract

  • Methods

  • Results

  • Discussion

    Briefly discuss training response – then cTn, then LV mass (explain why and how) then correlate …

    • 传统CVR降低
      -
    • 但cTnT升高,类似研究比较,考虑到坚实的证据,可能有因素影响了适应效应;
      -
    • 所有类似研究都没有考虑LVmass影响,但是我的结果组的训练前后变化不支持
      -
    • 相关分析也支持LVmass无关
      -
    • 急性运动的影响;机制
      -
    • 临床意义
      -
    • 研究限制与进一步工作
      -
    • 结论
      • Exercise training and artery function in humans: nonresponse and its relationship to cardiovascular risk factors

      —— 摘要;相关;
      ——We found that cardiopulmonary fitness improved, and weight, body mass index (BMI), cholesterol, and mean arterial pressure (MAP) decreased after training, while FMD% increased in 76% of subjects (P 0.001).
      —-With the exception of a modest correlation with total cholesterol (r  0.243, P 0.01), changes in traditional cardiovascular risk factors were not significantly related to changes in FMD% (P  0.05).
      ——exercise training-induced change in FMD% did not correlate with changes in traditional cardiovascular risk factors, indicating that some cardioprotective effects of exercise training are independent of improvement in risk factors.

      • Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart

      —— 摘要
      —— Endurance exercise training (ET) stimulates eccentric left ventricular hypertrophy (LVH) with left atrial dilation. To date, the biochemical correlates of exercise-induced cardiac remodeling (EICR) remain incompletely understood. Collegiate male rowers (n 9) were studied with echocardiography and maximal-effort cardiopulmonary exercise testing (MECPET) before and after 90 days of ET intensification.

    • cardiac troponin T (cTnT) measured by a highly sensitive assay
      cTnT levels measured with a highly sensitive assay

      • Low-volume, high-intensity, aerobic interval exercise for sedentary adults: VO₂max, cardiac mass, and heart rate recovery

      —— 摘要
      ——Purpose: The aim of this study was to compare the effects of low-volume, high-intensity aerobic interval training (HAIT) on maximal oxygen consumption (VO₂max), left ventricular (LV) mass, and heart rate recovery (HRR) with high-volume, moderate-intensity continuous aerobic training (CAT) in sedentary adults.

      Methods: Twenty-four healthy but sedentary male adults (aged 29.2 ± 7.2 years) participated in an 8-week, 3-day a week, supervised exercise intervention. They were randomly assigned to either HAIT (18 min, 180 kcal per exercise session) or CAT (45 min, 360 kcal). VO₂max, LV mass (3T-MRI), and HRR at 1 min (HRR-1) and 2 min (HRR-2) after maximal exercise were measured pre- and post-intervention.

      Results: Changes in VO₂max during the 8-week intervention were significant (P < 0.01) in both groups (HAIT, 8.7 ± 3.2 ml kg(-1) min(-1), 22.4 ± 8.9%; CAT, 5.5 ± 2.8 ml kg(-1) min(-1), 14.7 ± 9.5%), while the VO₂max improvement in HAIT was greater (P = 0.02) than in CAT. LV mass in HAIT increased (5.1 ± 8.4 g, 5.7 ± 9.1%, P = 0.05), but not in CAT (0.9 ± 7.8 g, 1.1 ± 8.4%, P = 0.71). While changes in HRR-1 were not significant in either group, change in HRR-2 for HAIT (9.5 ± 6.4 bpm, 19.0 ± 16.0%, P < 0.01) was greater (P = 0.03) than for CAT (1.6 ± 10.9 bpm, 3.9 ± 16.2%, P = 0.42).

    • 公用数据

    • 研究设计

    • 超声测试

    • 主要结果

    • Training response

      HIAT/CAT: VO2max+, body composition (fat-); CON VO2max-

    • cTnT response

      resting cTnT+

      1.横断观察研究几乎一致的发现,新颖的CV危险性标志物, cTn与体力活动水平呈负相关,然而较少纵向干预研究似乎并不支持体力活动导致安静cTnT降低这一因果关系。其中XX研究发现耐力训练升高、而力量训练并不改变安静cTnT。只有一项纵向研究发现阳性的结果:增加cTnT但增加值少于对照组。

      2.我们的结果训练导致了安静cTnT增加,这支持141#耐力训练的干预研究但扩展至HIAT及肥胖女性,进而我们的研究显示安静值的增加在HIAT和CAT并没有训差异,这进一步补充了141#,提示当控制了运动功率输出时训练产生的cTnT增加并没有训练方式的差异(独立于训练方式)。另外,cTn与传统危险因子也没有相关性。

      3.当现在的结果以及其他多数干预的纵向研究并不支持运动训练可导致cTnT降低时,我们似乎应慎重否认cTn作为一个训练标志物,这是因为已经有坚实的证据显示cTnT预测了心血管事件。因此我们推测很可能有混淆因素干扰了cTnT水平,以至于不能准确反映其训练效应。


      以下事实:CON恶化的VO2max,可能是由于实验跨过了假期,静态生活加重导致,并没有有影响cTn.

    • LVmass

      HIAT+; CAT-
      individual variation

      1. 尽管已经有人推测了LVmass可能是重要的影响因素,但仍没有实证研究探索。我们的随机对照的实验并不支持这个观点:HIAT与CAT都导致了cTnT的增加,但只有HIAT的LVmass增加but not in CAT,这似乎提示cTnT增加是独立于LVmass。另外,相关分析显示,两者并不相关性。
    • Correlation

      cTnT vs. LVmass -

      An unexpected finding of the present study was however the thinning of ST and PWT after training.

    • Implications

    • Limitations

      When best to assess resting levels and what other factors mediate resting levels

    • Conclusion

      • The effect of exercise training on the course of cardiac troponin T and I levels: three independent training studies

      ——摘要
      ——With the introduction of high-sensitive assays, cardiac troponins became potential biomarkers for risk stratification and prognostic medicine. Observational studies have reported an inverse association between physical activity and basal cardiac troponin levels. However, causality has never been demonstrated. This study investigated whether basal cardiac troponin concentrations are receptive to lifestyle interventions such as exercise training. Basal high-sensitive cardiac troponin T (cTnT ) and I (cTnI) were monitored in two resistance-type exercise training programs (12-week (study 1) and 24-week (study 2)) in older adults (>/=65 years). In addition, a retrospective analysis for high sensitive troponin I in a 24-week exercise controlled trial in (pre)frail older adults was performed (study 3). In total, 91 subjects were included in the final data analyses. There were no significant changes in cardiac troponin levels over time in study 1 and 2 (study 1: cTnT -0.13 (-0.33-+0.08) ng/L/12-weeks, cTnI -0.10 (-0.33-+0.12) ng/L/12-weeks; study 2: cTnT -1.99 (-4.79-+0.81) ng/L/24-weeks, cTnI -1.59 (-5.70-+2.51) ng/L/24-weeks). Neither was there a significant interaction between training and the course of cardiac troponin in study 3 (p = 0.27). In conclusion, this study provides no evidence that prolonged resistance-type exercise training can modulate basal cardiac troponin levels.

      • Familial aggregation of V˙ O2max response to exercise training: results from the HERITAGE Family Study
        -
      • High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014

      —— 大研究中的亚研究
      ——This is a substudy of NEEDED (North Sea Race Endurance Exercise Study) 2014. Details of the NEEDED design and the principal results have been previously reported.1 In brief, this is a

    • The present analysis is a sub-study of the North Sea Race Endurance Exercise Study (NEEDED) 2018. We assessed the change in CAC between the baseline CCTA acquired in either the NEEDED 2013 or 2014 study 7,8 and the follow-up CCTA assessment in 2018 (Figure S1). NEEDED 2018 was approved by the Regional Ethics Committee (REK 2013/550 and REK 2018/63), in compliance with the Declaration of Helsinki. All participants signed informed consent forms prior to enrollment into the studies.

      • Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart

      —— 研究设计
      —— Study design. A prospective, longitudinal, repeated measures study design was utilized to examine biochemical profiles in human endurance athletes both at rest and during maximal effort exercise. Male student athletes participating in The Harvard Athlete Initiative, an on-going research program designed to address numerous issues relevant to athlete health and exercise physiology, took part in this study during the autumn of 2009. Individuals were considered eligible if they were 18 yr old and were newly matriculated, recruited members of the men’s varsity rowing team. Using previously published pre-post LV mass index data from our group derived from a similar population of male rowers undergoing a similar training stimulus (36), we calculated a necessary sample size of n 8 ( 0.05 and  0.8) for the current study.

    • 固定时间测试排除:昼夜节律

      • Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart

      —— 超声检测
      —— Echocardiography. Echocardiography was performed using a commercially available system (Vivid-I; GE Healthcare, Milwaukee, WI) with a 1.9- to 3.8-mHz phased-array transducer. Images were obtained after 20 min of quiet rest and were separated from a previous training session by 24 h. Two-dimensional, pulsed-Doppler, and color tissueDoppler imaging from standard parasternal, apical, and subcostal positions were performed. The two-dimensional frame rate was 50– 100/s, and the tissue-Doppler frame rate was 100/s for all images. All echocardiography was performed by a single trained sonographer. All data were stored digitally, and poststudy offline data analysis (EchoPac, version 6.5; GE Healthcare) was performed by a study cardiologist blinded to the study time point. Definitions of normalcy were adopted from the most recent American Society of Echocardiography guidelines (13). Left ventricular (LV) ejection fraction, end-diastolic volume, and end-systolic volume were calculated using the modified Simpson’s technique. LV mass was calculated using the area-length method. Relative wall thickness was defined as [interventricular septal thickness (mm) posterior wall thickness (mm)/LV internal end-diastolic diameter (mm)]. LA volume was calculated using the biplane arealength method in apical four and two-chamber views. Peak longitudinal LV and right ventricular (RV) tissue velocities were measured offline from two-dimensional color-coded tissue Doppler images an reported as the average of three consecutive cardiac cycles. LV strain was measured by speckled-tracking analysis in the apical four-chamber view and is reported as the average of the six LV segments (basal, midventricular, and apical segments of the interventricular septum and the lateral LV wall). RV strain was measured by tissue Doppler analysis from the apical four-chamber view by placing a 6 2 mm region of interest in the mid-RV free wall at a location half way between the apex and the tricuspid annulus at end diastole. The location of this region of interest was manually adjusted in each systolic frame to ensure optimal tracking of the mid-RV free wall throughout RV systole. The reported value is the average of three consecutive cardiac cycles. Resting heart rates were obtained from the final loop of each study. Body surface area was calculated using the Mosteller formula (17) and all measurements are presented both as raw data and adjusted for body surface area when appropriate.

      • Sex-related differences in left ventricular structure in early adolescent non-professional athletes

      —- LVmass计算

    • *Evidence of direct cardiac damage following highintensity exercise in chronic energy restriction

      —- 意味着什么?
      —- the main findings suggest that individuals who habitually restrict their calorie intake below their bodies’ daily energy requirements, may have elevated biomarkers of exercise-induced myocardial stress from performing high-intensity exercise.

      • Exercise training and artery function in humans: nonresponse and its relationship to cardiovascular risk factors

      —— 心肺适能改善,脂肪降低、“传统危险因素” 不相关
      ——In agreement with previous meta-analyses (7, 8, 18, 35), our pooled analysis revealed relatively modest improvements intraditional cardiovascular risk factors, such as body weight (-0.6 kg), mean arterial pressure (-3 mmHg), and total cholesterol (-0.2 mmol/l).

      Furthermore, these changes in traditional risk factors did not relate to changes in endothelial function after training. Our observations reinforce the presence of a “risk factor gap” (12, 17): the concept that the relatively modest changes in traditional risk factors induced by exercise training (32) cannot fully account for the large clinical benefit of a physically active lifestyle (21, 25). Assessment of endothelial function has powerful predictive capacity for future cardiovascular disease, independent of other risk factors (26). The improvement in endothelial function after training is largely independent of change in risk factors. Clinically, this highlights that the cardioprotective benefits of training should not simply be viewed as those associated with easily measured, traditional cardiovascular risk factors.
      -
      与以前类似的研究一致,两种训练显著改善了传统危险因素,包括:VO2max、Fat、BMI.

    • VO2max、Fat、BMI

      -
      marked improvements in cardiovascular disease risk factors () in HIAT and CAT were equivalent and consistent with previous studies (Zhang,2020) using…

      • Low-volume, high-intensity, aerobic interval exercise for sedentary adults: VO₂max, cardiac mass, and heart rate recovery

      —— 描述结果
      ——Matsuo et al. (2014) showed that an exercise program comprising an 8-week, 5-day a week, high-intensity aerobic interval training (HAIt) markedly improved maximal oxygen consumption (˙VO2max) in sedentary male subjects. the study also found that the ˙VO2max improvement in HAIt was greater than that in moderate-intensity continuous aerobic training (cAt) and that the left ventricular (lV) mass significantly increased in HAIt, but not in cAt, even though the exercise volume and duration of HAIt were substantially lower than of cAt.

      • Impact of moderate physical activity on the longitudinal trajectory of a cardiac specific biomarker of injury: Results from a randomized pilot study of exercise intervention

      ——与观察研究比较,纵向研究的优势
      ——It is of particular interest to compare these findings with those we observed in the Cardiovascular Health Study (CHS), the observational cohort that generated the hypothesis being tested in this study. In that study, a much greater range of physical activity was observed among adults on average 5years younger than in the present study, and with longitudinal change in hs-cTnT assessed for 2 to 3years rather than 12months.4 That the differences in hs-cTnT seen in this pilot randomized trial are smaller than what we observed in the CHS could be the result of the 2- to 3-fold shorter duration of the LIFE-P trial than the observation period in the CHS and much smaller differences in physical activity kcal/wk compared with the most sedentary and most active subjects in the CHS. Furthermore, the randomized nature of the present study addresses a principal limitation of the CHS analysis or any observational study that does not make it possible to determine whether physical activity is a direct cause for lower cTnT level rises over time or whether lower cTnT rises is simply a marker of better heart health in people who are therefore able to exercise more.

      • The effects of exercise on cardiovascular biomarkers in patients with chronic heart failure

      ——谨慎解释数据
      ——A recently published meta-analysis of 10 studies that included 565 patients found exercise to decrease natriuretic peptide levels; however, understanding the results needs cautious interpretation of the data as well as confirmation within a randomized trial, which the current study provides using almost twice as many participants (n = 928).1

      • Sex-based differences in serum cardiac troponin I, a specific marker for myocardial injury, after cardiac surgery

      —- 先排除。。。影响
      —- It is important to emphasize that cardioplegic protocols were identical in both men and women enrolled in this study. Therefore, differences found in the present study cannot be attributed to intraoperative myocardial preservation techniques.

      • Endurance exercise training volume is not associated with progression of coronary artery calcification

      —— 阳性率 与其他研究比较
      —— In the present cohort, the prevalence of CAC at baseline was 34%, with a median CAC of 0 (0-6) Agatston units. For subjects with CAC at baseline, the median CAC was 12 (3-37) Agatston units. Thus, the baseline CAC score in the present cohort was comparable with the CAC scores in similar age groups from other population-based cohorts,23,24 but lower than previously reported in highly active subjects.3-6,25 During the 4.1 ± 0.3 years of follow-up, only 15 subjects (25%) had progression of CAC = 10 Agatston units. The mean ? CAC was 15 ± 40 Agatston units. This rate of progression of CAC was modest compared with other studies of the progression of CAC on CCTA.13,21,22,26-28 In the Heinz Nixdorf Recall Study (HNRS), subjects 45-50 years of age had a mean ? CAC progression of 38 Agatston units over a 5-year period.21 In HNRS, authors reported that once the CAC process had begun, the progression of CAC followed an exponential trajectory.2

    • 训练效应

      与141#一致,但有些研究不一致(没有变化)。
      解释这个不一致,可能与采血点的选择有关?引出:48小时仍然高,以前的观察窗口短,延长时会发现仍升高。

      • High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014

      ——本研究,支持 另外一项研究的效度。
      ——In the current study, we demonstrate for the first time an association between current snus tobacco use and lower cTn concentrations in the resting state. This lends further support to the validity of the finding of an inverse association between tobacco smoking and cTn observed in the population-based setting.16,17
      ——The current results, combined with data from prior reports observing an inverse association between cigarette smoking and concentrations of cTn, suggest that the effect is real and underscore the need for further experimental research exploring the potential underlying mechanisms for this apparently paradoxical phenomenon.

    • 解释为何cTnT升高:急性运动的影响未恢复?

      • early evaluation of myocardial injury by means of high-sensitivity methods for cardiac troponins after strenuous and prolonged exercise
        —- it is important to also consider the higher baseline cardiac troponin levels measured in professional endurance athletes.53 These values could be due to the high and prolonged exercise training that they carry out daily. in fact, professional endurance athletes train at least 6 times every week for at least 4-6 hours each session. it is logical to think that this strenuous and continuous training raises cardiac troponin levels, without the necessary rest time to return to normal biomarker levels.53, 57 in fact, several studies have shown that after an intense exercise or an endurance race it takes about 24-48 hours to measure normal troponin values in athletes.3, 57, 58 on the other hand, however, several authors have shown that even after an amateur physical activity there is a significant increase in cardiac troponin, however without ever exceeding url.59-61 These studies have opened an interesting scientific debate on the beneficial role of physical activity, on the right amount of physical exercise and in particular on the effects that intense physical effort can have on the heart.2, 10, 53, 58 in fact, several studies have shown that troponin elevation could be a physiological response of the heart to exercise within a certain limit of effort, to become a paraphysiological or even pathological response if the physical effort is strenuous and prolonged.3, 11, 53, 58 already more than 2000 years ago, Hippocrates spoke of the “right dose” of exercise for health. a few years ago, Wilson et al.62 had described that long-term strenuous aerobic exercise could be associated with deleterious adaptive changes in cardiac structure, function and electrical activity.
    • 机制

      安静释放以及训练升高的机制

      • Metabolic syndrome is associated to high-sensitivity cardiac troponin T elevation

      —- 我们的结果与以前的研究一致,但我们的研究有新贡献
      —-Because not all of these patients will go on to develop overt heart failure or other CVD, more accurate and personalized risk assessment is needed. The findings of the ARIC sub-analysis suggest that hs-TnT testing can further refine risk stratification in patients with MetS. Our results corroborate this concept in that it establishes not only an association between Mets and hs-Tn but suggests a continuous relation between the metabolic burden (i.e. the number of MetS components) and hs-TnT in asymptomatic subjects.

      • The effect of exercise training on the course of cardiac troponin T and I levels: three independent training studies

      ——高敏、危险分层、坚实的证据、可干预、受生活方式影响如运动训练
      ——The development of increasingly sensitive assays for cardiac troponin has now reached the point where cardiac troponin concentrations can be accurately assessed in the majority of subjects from a healthy reference population1. Parallel to the development of assays with increasing sensitivity, interest in cardiac troponin has expanded from acute cardiac care to risk prediction and risk stratification2. Studies in various patient groups and asymptomatic individuals have provided compelling evidence that baseline cardiac troponin levels predict outcome3. Interestingly, the observed risk gradient is not restricted to elevations above the 99th percentile, but is even apparent within the ¡°healthy¡± population reference interval, and independent of traditional risk factors such as age, sex and diabetes4¨C9. In the Framingham heart study, the basal cardiac troponin I concentration adds prognostic value to standard risk factors for predicting death, and cardiovascular disease10. Furthermore, temporal increases in cardiac troponin concentrations over time confer additional cardiovascular risk, and are inversely related to the level of physical fitness7,11. These observations form the basis of the hypothesis that cardiac troponin is a modifiable parameter, which may be receptive to lifestyle interventions such as an exercise training program.

      • The effect of exercise training on the course of cardiac troponin T and I levels: three independent training studies

      ——与其他研究比较
      ——In a recent study with (pre) frail subjects we tested the hypothesis that a supervised resistance-type exercise training program can influence the course of cardiac troponin levels over time12. However, this 24-week supervised bi-weekly exercise training program conferred no beneficial effect on the course of cardiac troponin T levels, despite substantial improvements of these subjects at the level of physical performance12. This negative study was conducted in frail and pre-frail subjects, characterized by substantially elevated baseline cardiac troponin levels, and therefore theoretically most amenable to the potential benefits of an exercise intervention. A possible drawback however, was the limited training load that could be imposed due to the level of frailty of these older subjects. Nevertheless, despite these limitations, our results were similar to those of other recent reports: 14-week endurance training in untrained adults13, 17-week half-marathon training in previously sedentary men14, and 3-month exercise training in heart failure patients (NYHA class II-IV)15 did not result reduce basal cardiac troponin T concentrations. However, limitations of these studies were the low basal cardiac troponin concentrations13 and the use of conventional instead of high-sensitive cardiac troponin T assays14,15 which reduced the power to detect an effect. Another issue that merits attention is that the effect of training intervention on cardiac troponin I has never been assessed. Since cardiac troponin T and I are two different proteins of the cardiac troponin complex with different biochemical characteristics16 and distinct release patterns17, both cardiac troponins may also respond differently to lifestyle interventions. The aim of the current study is 1) to overcome the limitations of previous studies, and 2) to examine the effect of exercise training on basal cardiac troponin I levels. Therefore, we now present two additional exercise training studies to the effect of a more intense training regimen on the course of high-sensitive cardiac troponin T and I levels in older adults, a population that often exhibits elevated basal cardiac troponin concentrations. Additional high sensitive troponin I was measured in our previously conducted study in (pre)frail subjects in order to present a complete and comprehensive overview to the effects of three supervised training programs.

      • Low-volume, high-intensity, aerobic interval exercise for sedentary adults: VO₂max, cardiac mass, and heart rate recovery

      —— 描述结果
      ——Matsuo et al. (2014) showed that an exercise program comprising an 8-week, 5-day a week, high-intensity aerobic interval training (HAIt) markedly improved maximal oxygen consumption (˙VO2max) in sedentary male subjects. the study also found that the ˙VO2max improvement in HAIt was greater than that in moderate-intensity continuous aerobic training (cAt) and that the left ventricular (lV) mass significantly increased in HAIt, but not in cAt, even though the exercise volume and duration of HAIt were substantially lower than of cAt.

    • 本来假设,但结果却是

      • The infarct size of cardiac or skeletal muscle has been estimated by means of serial CK analysis in the blood based on the hypothesis that the amount of increase in CK is proportional to the amount of damage (2,4,11,20,24). Therefore, it was expected that Group A (two arms were exercised on the same day) should show an approximate two-fold increase in plasma CK compared with one exercise bout for Group B (only one arm was exercised on each bout). That is, Group A would have shown more than 5,000U/l of peak CK, since the mean peak CK value on the right and left arm bout for Group B was 2,704 U/l, and 2,501 U/l, respectively. However, no significant difference was found in the pattern of change and the peak CK values between Group A and Group B (either bout) (Fig. 2). In addition, the distribution of post-exercise peak CK values was similar between groups (Table 1). It should be noted that the CK response varied from subject to subject as shown in previous studies (18, 19). In this study, the subjects showed more than 25-fold (Group A) or more than 40-fold (Group B) ranges in CK response (Table!). Since the subjects were randomly placed into Group A or Group B, it seems unlikely that one of the groups consisted of more high or low CK responders. Therefore it can be assumed that the similar CK response between Group A and Group B after exercise did not happen by chance.
    • 个体差异

      • Individual patterns of response to traditional and modified sprint interval training
        —- Considering V̇ O2max is a strong independent predictor of all-cause mortality and morbidity (Kodama et al., 2009), the presence of heterogeneity in observed V̇ O2max responses to exercise training is important to understand (Bouchard et al., 1999).
    • 解释机制

    • LVmass+VO2max一起讨论

      “This study demonstrated that 6 wk of HIIT but not MICT lowered cardiac afterload…”

    • LVmass 单独讨论

      “This study demonstrated that 6 wk of HIIT but not MICT lowered cardiac afterload…” 这是由于心肌肥大的幅度取决于强度、MCT没有效果可能是训练频率低,应达到每周5次。

    • 描述 不相关

    • 解释 不相关

      横断研究显示相关:缺乏急性运动的影响;横断研究老年人多病理肥大,而本研究属于生理性肥大?

    • 本研究的贡献

      • Relation of Lifestyle Factors and Life’s Simple 7 Score to Temporal Reduction in Troponin Levels Measured by a High-Sensitivity Assay (from the Atherosclerosis Risk in Communities Study)

      —— 观察,生活方式影响 cTnT 有什么价值
      ——Cardiac troponin is a standard biomarker used to diagnose myocardial infarction in the setting of chest pain. New highly sensitive assays for cardiac troponin can detect concentrations 10 times lower than earlier assays, extending its potential utility to monitoring cardiovascular risk in asymptomatic populations.1 Previous studies have demonstrated that a significant proportion of healthy middle-aged adults have detectable cardiac troponin T using a highly sensitive assay.2 The presence of detectable high-sensitivity cardiac troponin T (hs-cTnT) is believed to reflect subclinical myocardial damage and has been shown to strongly predict cardiovascular morbidity and mortality.3,4 Moreover, temporal decreases in hs-cTnT demonstrate a lower risk of cardiovascular events relative to patients with no significant change.4,5 Evidence suggests that hypertension, obesity, and diabetes are important risk factors for temporal changes in hs-cTnT.6,7 Because these clinical risk factors are influenced by lifestyle, the impact of health behaviors on temporal decreases in hs-cTnT is of substantial clinical interest. Identifying modifiable lifestyle factors associated with temporal reductions in hs-cTnT has potential utility for monitoring the beneficial impacts of health behaviors on cardiovascular risk during the subclinical period. The primary objective of our study was to investigate the associations between lifestyle-related health behaviors and 6-year decreases in hs-cTnT.

      —-Identifying favorable lifestyle and other variables associated with temporal reductions in hs-troponin is increasingly relevant, as this assay tracks well with clinical risk.4,5 Several studies have now shown that temporal reductions in hs-troponin are associated with relative reductions in clinical events.4,5,16 This finding suggests the potential of hs-troponin to serve as a dynamic and individualized marker of CVD risk that may respond to preventive interventions.17 Changes in high-sensitivity troponin over time may be used in clinical practice as a marker of the impact of lifestyle modifications on cardiovascular health to counsel patients during the subclinical period. Moreover, subclinical markers may serve as tools to increase medication compliance and to motivate patients’ behavior change.18

      ——Multifaceted lifestyle interventions that target several different health factors may have a greater impact on progression of subclinical cardiac disease than any single lifestyle factor alone.28 As such, our results suggest that hs-cTnT may be a useful clinical tool for monitoring the effects of lifestyle interventions on cardiac health in the primary care setting.5 Other cardiac biomarkers have shown prognostic value in assessing future cardiovascular risk during the subclinical period as well,29 but further research is necessary to determine the association between these cardiac biomarkers and changes in lifestyle factors.

      ——These data add to growing evidence that hs-cTnT may be a useful cardiovascular surrogate that is altered in response to lifestyle and behavioral risk factors

      • Cardiac Troponin T in Healthy Full‑Term Infants

      —— 这个发现是重要的,因为…
      —— The broad range in hs-cTnT seen in our study indicates that even significantly elevated values during this time period might be considered normal. These findings are important, since cTnT and hs-cTnT is used in the NICU to investigate possible cardiac insults due to, e.g., asphyxia, and a misinterpretation of elevated values might result in unnecessary interventions.

      —— 使用cTn作为…应小心
      ——-These findings underline the need of caution when using single hs-cTnT values as markers of cardiac damage in newborn infants, and even repeated sampling might be of limited use in the clinical setting since the change of hs-cTnT over time is still not fully understood.

      • High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population

      —- 危险性标志物 重要的 具备条件 特征
      —-Two additional key requirements for a biomarker in the setting of CV risk screening is to be responsive to modifications of the CV risk and to interventions that effectively modify this risk, such as statins.
      —-In a randomized study involving 307 elderly individuals (aged 70 or older), the adoption of a moderate level of physical activity attenuated the increase in hs-cTnT induced by aging at 12 months, in comparison with a sedentary lifestyle.51

      ——指导生活方式的干预
      —-The guidance of lifestyle interventionmay be another potential application if the response of hs-cTn is confirmed by further trials.

    • 运动 生活方式 好处

      • early evaluation of myocardial injury by means of high-sensitivity methods for cardiac troponins after strenuous and prolonged exexrcise

      —-It is unanimously accepted that regular physical exercise is part of a healthy lifestyle.1, 2 indeed, a plethora of experimental and clinical studies have definitively demonstrated that regular physical activity is associated with reduced cardiovascular risk and mortality rate for cardiac disease.1-3 in particular, a lot of evidence from large population-based, prospective observational studies has shown that maintaining or improving fitness is associated with lower cardiovascular disease risk; on the contrary, low cardiorespiratory fitness is associated to increased risk for myocardial dysfunction and morality cardiac rate.1-3

    • 微小增加即有意义

      • early evaluation of myocardial injury by means of high-sensitivity methods for cardiac troponins after strenuous and prolonged ex

      —-These data are well in accordance with some recent results reporting that even small, but progressive increments of hs-cTni values (such as about 5 ng/L) can significantly increase the cardiovascular risk in asymptomatic individuals in a general population.

      29.Association of repeatedly measured high-sensitivity-assayed troponin i with cardiovascular disease events in a general population from the MorGaM/Biomarcare Study. clin chem 2017

      • High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population

      —- 微小的升高有意义
      —-More recent evidence confirms that even minimal elevations of hs-cTn concentration within the normal range, i.e. below the 99th percentile of normal, may predict CV disease and mortality in the asymptomatic individuals.

    • 规律运动的人不应纳入cTn范围研究

      • How is cardiac troponin released from injured myocardium?
        ——In addition, as indicated above, normal subjects and even healthy athletes show cTn increases in association with heavy endurance exercise. Individuals performing such heavy physical activities regularly, therefore, should not be included in future cTn normal range studies for cTn assays with high analytical sensitivity. As a further example, consider an individual with hypertension and left ventricular hypertrophy who has a baseline value
    • 安静值:危险分层也有价值

      • How is cardiac troponin released from injured myocardium?
        ——As a further example, consider an individual with hypertension and left ventricular hypertrophy who has a baseline value for hs-cTn near the upper reference limit (URL). His postoperative cTn values could easily exceed the URL with a small to modest increase in response to volume expansion and/or catecholamine treatment, which could be consistent with a normal response. If this is true, we should not consider such increases to be clinically relevant. Indeed, in this example suggested, it may be that the cTn baseline concentrations are more relevant for risk stratification similar to exercise stress testing in patients with stable CAD.13
      • High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014

      —— 训练,是个干扰因素
      ——Use of smokeless tobacco is associated with lower circulating cardiac troponin concentrations both in the resting state and after exercise, and tobacco use should be taken into account when interpreting cardiac troponin test results.
      ——训练,干扰了cTn与心血管健康的关系
      ——Although the clinical applicability of the results is unknown, it signals that smokeless tobacco use may confound the association between cTn and cardiovascular health.

      • Association of novel biomarkers of cardiovascular stress with left ventricular hypertrophy and dysfunction: implications for screening

      —— 此结果并未否认cTn的诊断价值,而是提示LVmass作为一个混杂因素/无关变量,这特别重要的在…情况下
      ——The influence of LVH on cTnI release after myocardial damage reported here does not invalidate the use of troponins as surrogate markers, but shows the need to take LV mass into account as an important potential confounding factor in clinical and research evaluations. These considerations could be especially important in determining the significance of small increases in circulating troponin in patients presenting to the emergency department, given that troponin readings in patients with LVH may give a false-positive diagnosis of MI.36 In this regard, mild increases in troponin-I37–40 or troponin-T41 have been reported in patients with LVH in the absence of chest pain or any other acute condition. In addition, it has been recently reported that cardiac troponin concentrations correlate with LV mass index independent of coronary artery disease status in patients with aortic valve stenosis.42,43 Presence of a dynamic pattern (rise and/or fall) in cardiac troponin values along with clinical evidence of ischemia can be of help to confirm the diagnosis of MI in these contexts. Although the aims of our study were beyond these important issues, our data support that, for a given small stress to the myocardium, troponin release in patients with LVH might be larger than in patients with normal LV mass.

    • 提示未来的研究方向

    • 寻找最佳测试点或窗口

    • 安静值另外的影响因素

    • 更长的训练期

      • Measurement of circulating concentrations of cardiac troponin I and T in healthy subjects: a tool for monitoring myocardial tissue renewal?
        —-In conclusion, some recent findings (33, 38–43) may explain why plasma troponin concentrations are increased in the absence of myocardial necrosis in some pathological conditions. However, we cannot exclude other mechanisms, independent of myocardial necrosis and integrin-mediated myocardial stretch that might be involved in the degradation and release of troponins from myocardial cells. Further studies are necessary to accurately describe the cellular mechanisms responsible for the release of cTnI and cTnT from damaged and/or viable cardiomyocytes.
      • High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014

      ——不能外推至另外的人群
      ——Third, our study includes a White cohort and the sample mainly included snus-using men. The findings may not be generalizable to individuals of other ethnic groups or to women.

    • 样本量小

      —— First, we acknowledge that our sample size was relatively small. However, our use of a longitudinal, repeated measures study design in which each individual acted as his own control maximized our ability to define causal relationships between ET and NP release.In addition, the use of a prior power calculations coupled with the directional consistency of our pre- and post-echocardiographic data (Fig. 1) provides reassurance that we were amply powered to capture meaningful physiologic change and that our aggregate results are not driven by outliers (type 1 error).

    • 超声测试 不如 MRI

      ——Third, we acknowledge that echocardiography may produce relatively inaccurate absolute estimates of LV mass compared with cardiac magnetic resonance imaging. However, our favorable intraobserver variability data, explained by the use of a single trained sonographer and a single experienced interpreter of echocardiographic data, emphasize the accuracy of the observed changes in LV mass between the two study time points.

    • 其他心腔

      • Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart

      —— 其他心腔的影响
      —— Finally, we are unable to comment on the relative contributions of individual cardiac chambers to levels of postexercise plasma NP levels. Future work will be required to clarify whether both right- and left-sided atria and ventricles contribute similarly to this phenomenon.

      • Relation of Lifestyle Factors and Life’s Simple 7 Score to Temporal Reduction in Troponin Levels Measured by a High-Sensitivity Assay (from the Atherosclerosis Risk in Communities Study)

      —-只有两个观察点
      ——First, hs-cTnT was measured at only 2 time points; thus, we were unable to evaluate more granular trends in subclinical myocardial damage with various lifestyle factors

      • The effects of exercise on cardiovascular biomarkers in patients with chronic heart failure

      ——研究限制
      ——There are potential limitations to the present study. The population for this study was derived from the HFACTION trial and is susceptible to the limitations inherent in clinical trial populations. Biomarker measurements were made after 3 months of structured exercise training, and there is a possibility that changes in levels might have been noted after a longer exercise period. Our study population consisted only of patients with impaired ejection fraction (LVEF b35%), so our results cannot be extrapolated to the population of patients with HF and preserved ejection fraction. Our population consisted of ambulatory patients with NYHA class II and III HF, and these findings may not be generalizable to patients with less or more severe illness. We used a commonly used platform for measurement of cTnT, rather than the newer high sensitivity assays used in more recent studies of troponin elevation in HF.30

      • Impact of moderate physical activity on the longitudinal trajectory of a cardiac specific biomarker of injury: Results from a randomized pilot study of exercise intervention

      ——研究限制
      ——This study, by design, was intended as a feasibility pilot study to determine if older sedentary adults could be successfully randomized to a physical activity intervention and determine if this resulted in differences in physical performance. It was not designed to detect differences in clinical outcomes between the 2 groups, and a prior report of the LIFE-P results shows that there was not a significant difference in time to major mobility disability or death.13

      —-Another limitation is that not all enrolled subjects had baseline and 1-year blood samples available for measurement, which could potentially have biased our results. In the absence of information on clinical outcomes, we were unable to determine whether these small but significant differences in longitudinal progression of hs-cTnT levels are clinically meaningful.-

      —-Furthermore, the intensity of the physical activity intervention arm was moderate, as suggested by the achieved physical activity of 135minutes per week in this group, lower than the consensus guideline recommendation of 150minutes weekly.16

    • This has important implications, particularly when assessing patients with possible ACS in the Emergency Department.

      • High-Intensity Interval Training Improves Left Ventricular Contractile Function

      ——描述主要发现
      —— Typically, the exercise training effect on cardiac function is assessed by M-mode in echocardiography, which only displays the size of ventricular cavity, myocardial thickness, the integrity of interventricular septum, and the motion of ventricular wall at rest (8). The present study further contributes to a greater understanding of LV mechanical responses to various exercise regimens using stress echocardiography. In summary, HIIT for 6 wk induces eccentric myocardial hypertrophy, enhances myocardial performance, and reduces peak torsion to reduce energy consumption for myocardial contraction, thereby improving LV contractile function. On the other hand, this exercise regimen also improves diastolic function by increasing the Vp and the E/A ratio as well as reducing the time to reach peak untwisting velocity, consequently increasing SV. Although MICT modestly elevates myocardial contractility, cardiac diastolic function remains unchanged after this exercise intervention. The present findings provide a new insight into the superior effects of HIIT on LV mechanics during exercise by simultaneously increasing contractile and diastolic functions and may have important implications for exercise training in cardiac rehabilitation.

      • Impact of moderate physical activity on the longitudinal trajectory of a cardiac specific biomarker of injury: Results from a randomized pilot study of exercise intervention

      ——摘要
      ——BACKGROUND: In animal models, physical activity (PA) prevents cardiac myocyte cell death. Data for PA mitigating myocyte injury in humans are limited to observational studies. Using a randomized controlled trial design, we sought to determine if introducing moderate PA to previously sedentary older adults could reduce the trajectory of myocardial injury as measured by the high-sensitive cardiac troponin T (hs-cTnT) assay.
      METHODS: Participants (age >/=70 years) were assigned to a 1-year intervention of moderate PA or health education control. High-sensitive cTnT was measured at baseline and 1 year in the 307 of 424 subjects who had available stored serum. Changes in hs-cTnT within 1 year were compared between PA and control groups, as were differences in the proportion of subjects with a significant rise in hs-cTnT (prospectively defined as a>50% increase at follow-up from baseline). Moderate to vigorous PA in kcal/wk was estimated with the CHAMPS questionnaire.
      RESULTS: Baseline hs-cTnT levels and PA kcal/wk were similar for both groups. Activity kcal/wk increased in the PA, but not in the control group at 1 year. The median increase in hs-cTnT level from baseline was >3 times larger in the control (0.73 ng/L, interquartile range -0.64 to 2.59) vs the PA group (0.19ng/L, interquartile range -1.10 to 1.93) (P=.02). The proportion with a>50% increase in hs-cTnT was larger in the control group than in the PA group (9.3% vs 5.1%), but this difference was not statistically significant (P=.16).
      CONCLUSIONS: Initiation of moderate PA in sedentary older adults may favorably modify subclinical myocardial injury.

      • Association of Novel Biomarkers of Cardiovascular Stress With Left Ventricular Hypertrophy and Dysfunction: Implications for Screening

      —— 超声测量
      ——All attendees underwent standardized 2D transthoracic echocardiography with Doppler color flow imaging. A sonographer or a cardiologist (experienced in echocardiography), blinded to clinical information and biomarker results, read all echocardiograms. The reproducibility of echocardiographic measurements was excellent.14 Interobserver variability ranged from 0.9% to 5% for LVDD, from 2% to 2.9% for diastolic posterior wall thickness, from 3.6% to 6.5% for the interventricular septum in diastole, and from 0.8% to 4% for calculated LV mass. Corresponding figures for intraobserver variability ranged from 0.3% (LVDD) to 4% (interventricular septal thickness).14 Digital M-mode measurements from ¡Ý3 cardiac cycles were averaged to estimate LV internal dimensions in end-systole and enddiastole, and thicknesses of the interventricular septum and LV posterior wall at end-diastole (in accordance with the American Society of Echocardiography [ASE] guidelines).15 Fractional shortening (FS) was calculated using LV internal dimensions at end-diastole and end-systole. In all participants, visual assessment of LV global systolic function was performed in multiple views to estimate the LV ejection fraction (LVEF), which was categorized as normal (LVEF >0.55), borderline (LVEF 0.51 to 0.55), mildly reduced (LVEF 0.41 to 0.50), moderately diminished (LVEF 0.31 to 0.40), or severely impaired (LVEF ¡Ü0.30). The accuracy of the aforementioned estimation of LVEF has been validated in prior reports.16 Both the qualitative variable LVEF and the quantitative variable FS were used to define LV systolic dysfunction12 (ie, the presence of either abnormal LVEF or abnormal FS) because they provide complementary information: the former may not be sensitive for detecting subtle alterations in LV systolic function whereas the latter focuses on the base of the heart (and may miss diminished LV contractility in other regions)

      • High sensitivity cardiac troponins: Can they help in diagnosing myocardial ischaemia?

      —- LVH 判断标准
      —- All patients underwent a complete M-mode and two-dimensional echo Doppler study, carried out by commercial equipments with second-harmonic imaging (iE33 X-matrixUltrasound System, Philips, Andover, Massachusetts, USA). Left ventricular mass was calculated in each patient by means of M-mode echocardiography, using the equation of Devereux.7 A value >125 g/m2 (males) and 110 g/m2 (females) was considered as indicative of left ventricular hypertrophy (LVH).
      ——Devereux RB. Detection of left ventricular hypertrophy by M-mode echocardiography. Anatomic validation, standardization, and comparison to other methods. Hypertension 1987; 9: II9–II26.

    • *Association of Troponin T Detected With a Highly Sensitive Assay and Cardiac Structure and Mortality Risk in the General Population

      —- LVH 标准
      —- Cardiac and aortic MRI
      was performed using a 1.5-Tesla system (Intera; Philips Medical Systems, Best, the Netherlands). Left ventricular mass, wall thickness, end diastolic volume (LVEDV), and ejection fraction (LVEF) were calculated from short-axis sequences. Left ventricular hypertrophy (LVH) was defined as left ventricular mass greater than 89 g/m2 g/m2 in women and greater than 112 in men, based on a phenotypically normal subpopulation of the DHS cohort.20 Details of aortic MRI and compliance methods are presented in the eSupplement.

      • Association of novel biomarkers of cardiovascular stress with left ventricular hypertrophy and dysfunction: implications for screening

      —- LVH标准
      —- Additionally, we performed analyses using the ASE cut points (LVM/height ≥127 g/m in men and ≥100 g/m in women)15 to define LVH.

    • *Aerobic High-Intensity Intervals Improve V˙O2max More Than Moderate Training

      —- HIT MCT 最大摄氧量影响
      —- V˙ O2max. V˙ O2max is one of the primary determinants of aerobic endurance performance (1). The high–aerobic intensity interval training regimens of 15/15 and the 4 x 4 min performed at the same intensity both revealed significantly higher absolute V˙ O2max responses of 5.5 and 7.3%, respectively, over the moderate- and lower-intensity training of the O2 cost-matched LT and LSD training groups. The effect of interval training is in line with previous studies (7,13). It has been suggested a longer duration for training sessions could compensate for lower-intensity exercise (16,18). However, the present study, which matched four training protocols for total work and frequency, does not support this claim. Instead, our results are consistent with those of Wenger and Bell (29) and Thomas et al. (27), who found that intensity of training cannot be compensated for by longer duration. Improvements in V˙ O2max seem to be dependent on fitness level. In a recent paper, we have shown an improvement in V˙ O2max of 7% for cardiovascular patients pathology.

      • Effects of a low-volume aerobic-type interval exercise on VO2max and cardiac mass

      —— 摄氧量及体脂降低在HIT和MCT是相似的。
      ——Conversely, we observed no significant group difference in V¨B O2max improvement between SIT and CAT (P = 0.25), nor between SIT and HIAT (P = 0.35), whereas the V¨B O2max of the SIT significantly increased (16.7% T 11.6%; Fig. 3) and its ES was large (1.10) (Table 3). Improvements in SIT and CAT V¨B O2max were equivalent and consistent with previous SIT studies (1,22) using the modified Wingate protocol. The exercise volume of the SIT might have been too small, or the sample size of the studies might not have been sufficient to detect the difference between SIT and other protocols.”

      • The effect of a six-month resistance-type exercise training program on the course of high sensitive cardiac troponin T levels in (pre)frail elderly

      ——cTn角色转变;纵向研究、生活方式、缺乏干预研究
      ——Cardiac troponin is the preferred biomarker for diagnosing non-ST segment elevation myocardial infarction [1]. With the introduction of high-sensitivity assays, cardiac troponin levels became also detectable in apparently healthy subjects. This has expanded its role from acute cardiac care to risk stratification and prognostic medicine [2]. Meanwhile, high sensitive cardiac troponin (hs-cTn) has acquired the status of a prognostic biomarker that predicts cardiovascular risk, in addition to established Framingham risk factors (传统危险因素) such as age, sex, blood pressure, and dyslipidemia [3]. Despite the remarkable consistency in the literature on the association between cardiac troponin levels and increased risk for cardiovascular morbidity and mortality, it is unclear whether preventative measures such as lifestyle intervention programs can influence the course of basal troponin levels. Suggestive evidence in favor of this hypothesis was provided by an observational study by deFilippi et al., showing that higher physical activity levels in elderly subjects were associated with both lower basal cardiac troponin T (cTnT) levels, and a lower probability of a significant increase in cTnT concentrations between consecutive visits [4]. However, no intervention study has evaluated the effect of an exercise program on the concentration of cardiac troponin.

      • Impact of moderate physical activity on the longitudinal trajectory of a cardiac specific biomarker of injury: Results from a randomized pilot study of exercise intervention

      ——谨慎解释结果
      ——These findings should be considered cautiously with appreciation that the study was not designed to test the effect of physical activity on troponin levels.In fact, in sensitivity analysis, we did not find a correlation with positive outcomes of physical activity such as improvements in gait speed and body mass index and change in cTnT level. Moreover, the number of subjects with N50% increase in their hs-cTnT in the LIFE-P study was small and the difference between the 2 groups was not statistically significant. However, this finding is not without precedent, as the inflammatory marker interleukin-6, which is also associated with cardiovascular outcomes, correspondingly increased less in those LIFE-P participants assigned to physical activity vs successful aging.14 Potentially, the palliative effect of physical activity on cardiac injury may be mediated through an anti-inflammatory mechanism. A clinical correlate to support these biomarker findings is the marked reduction in cardiovascular risk that has been previously reported from observational cohorts of adults who increase their physical activity levels.7-10

      • High-sensitivity cardiac troponin T in young, healthy adults undergoing non-cardiac surgery

      —- 排除。。
      —- cTn assays have a nearly 100% cardiac tissue specificity, except for some patients with chronic muscular disease who have increased concentrations of circulating hscTnT because of re-expression of presumably fetal proteins.19e21 It is unlikely, therefore, that skeletal muscle injury during orthopaedic surgery caused postoperative cTn increases in our patient population.

      • Cardiac Troponin T in Healthy Full‑Term Infants

      —— 以前的研究,仍存在的空白
      —— Several studies have investigated cTnT values in infants after admission for neonatal care [3¨C5, 10¨C24]. Only a limited number of studies have determined cTnT values primarily in healthy full-term infants [1, 2, 25¨C28]. All but one of these studies have been performed before the introduction of hs-cTnT assays [2] and a considerable proportion of cTnT values were even below the detection limit [1, 25]. Cardiac troponin T has in most cases been determined either in cord blood [1, 2, 25, 26, 28] or in peripheral blood [3, 11¨C13, 17¨C19, 21, 29]. Only a few studies have done sequential measurements of cTnT, and primarily in asphyxiated or premature infants [5, 10, 16]. We aimed to investigate hs-cTnT values in cord blood and during the first week of age, in healthy full-term infants born either after spontaneous onset of delivery, or after planned caesarean section (CS). We hypothesized that hs-cTnT would be elevated already in cord blood, compared with the adult upper reference limit, and that it would further increase over the first 2¨C5 days of age. We finally hypothesized that hs-cTnT values would be higher in infants born after vaginal delivery compared with infants born after planned CS

      • Cardiac troponin I is released following high-intensity short-duration exercise in healthy humans

      —— 比较阳性率,不同人群
      —— The use of hs-cTnT for screening of the general population
      has been evaluated. In the Dallas Heart Study, a multiethnic population-based study, over a median of 6.4 years of followup, the prevalence of measurable cTnT above the limit of blank with the highly sensitive assay (≥3 ng/L) was 25% (versus 0.7% with standard assays).10 Of note, in the current study, the prevalence of hs-cTnT >3 ng/L was notably higher (78.5%), presumably due to the older age and larger proportion of males in the CCLS compared with the Dallas Heart Study. In the Dallas Heart Study, all-cause mortality and left ventricular hypertrophy increased significantly from the lowest hs-cTnT category (<3 ng/L) to the highest (≥14 ng/ L).10 In an older population enrolled in the Cardiovascular Health Study, the prevalence of hs-cTnT ≥3 ng/L was 66.2% and both the baseline hs-cTnT level and changes in troponin levels were found to provide prognostic information.11 In the Cardiovascular Health Study, we previously reported an association between regular exercise and smaller increases in hs-cTnT over time.18 However, the association with objectively measured CRF has not been reported previously.

      • Association of Troponin T Detected With a Highly Sensitive Assay and Cardiac Structure and Mortality Risk in the General Population

      —— cTnT阳性率
      ——Using a highly sensitivity assay, cTnT was detectable in approximately 25% of adults in the general population and was associated with structural heart disease and risk of subsequent all-cause mortality.

      • Impact of an endurance training program on exercise-induced cardiac biomarker release

      —— 讨论 安静值高 讨论相关
      —— We observed higher baseline and peak postexercise values for hs-cTnT after 14 wk of running training, which also differentiated this group from the control cohort. This supports some previous cross-sectional data from athletes of different training status (Legaz-Arrese et al., unpublished observations; and Ref. 24) but does contradict past field-based studies of runners with higher and lower selfreported training volumes (e.g., Ref. 20). The assay precision and method used to quantify the level of training may also be confounding factors in the relationship observed in previous studies. In the largest case series data in marathoners, Fortescue et al. (5) noted that the runners with less prior experience in marathon running were more likely to have cTnT increases. They also found no relationship between race time and the increase in cTnT, suggesting that the number of previous marathons may not be the most appropriate way to quantify the current level of training. Furthermore, the authors indicated no significant relationship between the release of cTnT and average training pace or average miles run per week during the last 3 mo. In the same direction, a multiple regression analysis demonstrated that marathon experience was a significant predictor of postmarathon hs-cTnT (19). Once again, the authors did not establish a relationship between marathon time and the release of hs-cTnT and did not gather other data on the level of training of the athletes. The association observed by Nie et al. (21) and Tian et al. (39) between the number of years of training and cTnT or cTnI release after a half-marathon in adolescent subjects was weak and could have been influenced by the maturity status of the adolescents. Moreover, in neither of these studies did the authors observe a relationship for other indicators of the level of training, such as weekly training distance. Finally, using a prospective study design, Mehta et al. (15) revealed that average miles run per week in the last 3 yr (an indicator of previous training experience) was negatively associated with postmarathon cTnI release. No association, however, was observed for the current training status (miles run per week in the last 4 mo) or for race time

      • Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart

      —— 结果:LVmass+,restingcTnT=, VO2max+

      • High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014

      ——概述运动性cTn及意义挑战
      ——提示进一步工作
      ——An increase in concentrations of cTn following intense exercise is commonly observed.2 Activity-related changes in serum enzymes have been known for several decades,18,19 and, in line with these observations, exercise-induced troponin increase has traditionally been considered a benign and physiological phenomenon. However, recent observations demonstrating associations between the magnitude of postexercise troponin response and cardiovascular disease and outcome20,21 challenge this concept. Moreover, it highlights that more detailed information is needed on determinants of the magnitude of transient elevations of cTn following exercise.

      • Individual variability in cardiac biomarker release after 30 min of high-intensity rowing in elite and amateur athletes

      —- 更高的安静值,解释机制
      —- We do not know the reasons behind the higher baseline cTnI levels in elite versus amateur rowers. A previous study showed that runners with detectable hs-cTnT were significantly better trained than runners in whom hs-cTnT was not detectable (Saravia et al. 2010). Furthermore, we found that a controlled endurance training intervention resulted in higher pre-exercise hscTnT values (Legaz-Arrese et al. 2015). One hypothesis is that this effect is due to successive training sessions and limited recuperation time for elite athletes. However, this seems unlikely to be a factor in this study because subjects were required to abstain from vigorous athletic activity for 48 h before the exercise test. Furthermore, if the greater baseline cTnI values were a consequence of incomplete recuperation, the elite rowers ought to have had similarly increased baseline NT-proBNP levels, based on the results of this study. In a previous study, significantly higher baseline hscTnT concentrations were found in males compared with females (Mingels et al. 2009). Given that mean heart size is larger for male and elite athletes than for female and amateur athletes (Legaz-Arrese et al. 2006; Legaz Arrese et al. 2005), it is reasonable to expect different reference cTn values between these groups. Future research may wish to address this issue.

    • *High-Sensitivity Cardiac Troponin After Cardiac Stress Test: A Systematic Review and Meta-Analysis

      —- 以前一直假定,但最近质疑
      —- Until recently—before the introduction of hs-cTn assays—it was widely assumed that cTn is only released during myocardial cell necrosis. Recent hs-cTn data, however, have strongly questioned this assumption. Data obtained from young, healthy athletes have shown that hs-cTn levels may rise…

      • Predictors of cardiac troponin release after a marathon

      —- 我们的研究有贡献,但机制仍需进一步研究,解决这个机制有重要意义
      —- Whilst our study provides novel insight into factors that relate to the exercise-induced increase in cTnI, studies are warranted to directly examine the underlying mechanisms of elevated post-race troponin levels. Such information will reveal important information regarding the physiological versus pathological nature of troponin release in athletes after exercise.

      • Cardiac Troponin T in Healthy Full‑Term Infants

      —— 原因不十分清楚,几种可能的解释
      —— What causes the transient rise of cTnT in newborn infants is not fully understood. One possible explanation could be the transient hypoxia related to delivery, in combination with the physiological circulatory adaptation starting after birth. The circulatory adaptation continues during the first days of life which might explain the elevated values of cTnT seen several days after delivery. It is not clarified at what time point cTnT reaches its highest levels postnatally nor when it equals adult reference values.

      • High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population

      —- 机制并未完全理解;解决机制有助于确定预防干预的新靶点。
      —- The predominate trigger and exact mechanisms of cTnT/I release from cardiomyocytes in asymptomatic individuals are incompletely understood.58 Elucidation of the underlying pathophysiology by studies addressing sensitive indices of CV function, besides improving our understanding, may further contribute to the identification of novel targets for preventive interventions.

    • 机制:心肌细胞更新

      • Early evaluation of myocardial injury by means of high-sensitivity methods for cardiac troponins after strenuous and prolonged exercise

      —— unfortunately, to date, the exact mechanism is unknown.5, 6, 23, 24
      ——an interesting question concerns the physiological interpretation of biomarker circulating levels, measured with hs-cTn methods, in healthy subjects at rest. Several authors have suggested that the hs-cTn concentration is a reliable index of physiological cardiomyocyte renewal.5, 7, 8, 23, 24 indeed, the 99th percentile url values of hscTni methods (about 14-47 ng/l) correspond to the same amount of cardiomyocyte renewal evaluated in experimental animals and adult subjects.5, 7, 8, 23, 24

      —— 中位数与99th差10-15倍:细胞更新需增加10-15倍才能达到99th阈值也就是心肌损伤阈值results can be explained by considering that the distribution of hs-cTni values in healthy adult subjects is markedly asymmetrical: as a consequence, the 99th percentile url value is up to 10- to 15-fold higher than the median value (Table i). This means that the physiological cardiomyocyte renewal should increase 10-15 folds before the hs-cTn concentration value can exceed the threshold of myocardial injury.7, 8, 16, 35

      • Relation of Lifestyle Factors and Life’s Simple 7 Score to Temporal Reduction in Troponin Levels Measured by a High-Sensitivity Assay (from the Atherosclerosis Risk in Communities Study)

      —— 我们的研究扩展这个发现 ,到 HIT
      ——Additionally, sedentary behavior was associated with progression of subclinical myocardial damage, whereas moderate physical activity appeared to have a protective effect in older adults. Our study extends these findings to a middle-aged population and demonstrates the benefit of other health behaviors, such as maintaining both a normal weight and a favorable LS7 score.

      • The effect of exercise training on the course of cardiac troponin T and I levels: three independent training studies

      ——以前是横断研究、现在看因果关系,老年人基础水平高,易受影响,避免最后一次训练的影响,证实以及扩展了以前的研究:提高了素质但cTn无影响
      ——In two independent supervised training studies of 12 and 24 weeks respectively, we found no effect of resistance-type exercise training on the course of cardiac troponin T and I levels in older subjects, nor did we find an effect of a 24-week training program on cardiac troponin I levels in (pre)frail subjects. Our results do not support the idea that cardiac troponin levels might be modifiable through exercise. This hypothesis was postulated by observational studies, showing that higher physical activity levels in older subjects were associated with both lower basal cTnT levels, and a lower probability of a significant increase in cTnT concentrations between consecutive visits11,26. To investigate whether a causal relationship underlies this association, we conducted a series of training studies in subjects where stable elevated cardiac troponin levels are common, and who are therefore -at least theoretically- most receptive to the favorable effects of an intervention. To ensure that basal cardiac troponin levels, rather than acute post-exercise effects were studied, we included a three day interval between the last training session and the blood sampling procedure27. None of these studies showed a favorable effect of resistance-type exercise training on cardiac troponin levels. The non-responsive pattern of troponin T and I to an exercise program is in contrast with the beneficial changes observed for leg strength, muscle mass, insulin sensitivity, HbA1c, total cholesterol and LDL18–20,22,23. The present results confirm and extend the results of our previous training intervention study in (pre)frail older adults12, which was also characterized by favorable effects on physical performance, but a lack of effect on circulating cardiac troponin levels.

      • Contrary to our hypothesis, there was no statistical difference in the incidence of response across any of the 3 SIT protocols. In addition, potential differences in biological sex were explored with no apparent sexually divergent response as males and females had similar incidences of response in aerobic capacity, aerobic performance, and anaerobic capacity (except for peak and average speed). This finding that females were more likely to be responders for time to peak speed whereas males were more likely to be responders for average speed is surprising. Future work should explore this further and investigate possible mechanisms explaining these findings. Overall, these results are particularly important in light of our previous research demonstrating SIT with short exercise bouts has improved psychological perceptions (Townsend et al., 2017) while maintaining several key physiological responses (Islam et al., 2017).

        • Exercise training and artery function in humans: nonresponse and its relationship to cardiovascular risk factors

        —— 个体差异;不均匀性
        ——Despite the overall health benefits of exercise training, recent studies have described heterogeneous adaptations to training (28). In subjects who undertook similar exercise training interventions, some demonstrated large improvements in parameters such as cardiopulmonary fitness, blood pressure, and cholesterol, while others exhibited smaller increases or even “adverse” responses (4, 5). Such findings are consistent with anecdotal clinical observations that some individuals only respond modestly to exercise. No previous study has explored the heterogeneity of changes in artery function or health in responses to exercise training, or tried to identify predictors of training-mediated adaptations in arterial function. A widely accepted index of artery function and health is flow-mediated dilation (FMD%), the vasodilator response to an imposed shear stress stimulus following cuff-induced increases in blood flow. Recent studies indicate that brachial artery FMD% is a surrogate for the assessment of coronary artery endothelial function (30) which predicts cardiovascular outcomes in humans (11, 15, 26).

        ——We found that 24% of the subjects demonstrated no change in endothelial function with training. Although no previous study has reported the heterogeneity in arterial adaptation to exercise training, recent publications by Bouchard and colleagues have raised the general concept of a lack of responsiveness to exercise training (4–6). The authors suggested that training may have an “adverse” impact on some risk factors (e.g., blood pressure, triglycerides, HDL), in certain individuals (4, 5). Whether such adverse effects translate into poor clinical outcomes is unknown, especially since CVD risk assessment is typically undertaken by examining a cluster of biomarker and/or risk factors. Nonetheless, these observations demonstrate that the effects of training are not simply unidirectional, an important message when evaluating

        • Cardiac Troponin T in Healthy Full‑Term Infants

        —— 原因不十分清楚,几种可能的解释
        —— What causes the transient rise of cTnT in newborn infants is not fully understood. One possible explanation could be the transient hypoxia related to delivery, in combination with the physiological circulatory adaptation starting after birth. The circulatory adaptation continues during the first days of life which might explain the elevated values of cTnT seen several days after delivery. It is not clarified at what time point cTnT reaches its highest levels postnatally nor when it equals adult reference values.

        • High-Intensity Interval Training Improves Left Ventricular Contractile Function

        ——HIT和MCT的不同效应,以及与其他研究的比较
        —— Echocardiographic strain/SR analysis is a new noninvasive method for the early detection of segmental myocardial dysfunction (13). In this longitudinal study, HIIT simultaneously enhanced the radial strain/SR in basal and apical segments, whereas MICT only increased the radial strain/SR in the apical segment. Eun et al. (15) and Charfeddine et al. (26) have reported that endurance athletes exhibited greater circumferential strain at the basal segment and radial/circumferential strains at the apical segment than did healthy untrained subjects. These previous findings (15,26) were consistent with part of our results. However, these previous investigations were cross-sectional studies (15,26), that the favorable cardiac functions among the well-trained athletes may be only partially attributable to physical training, and that the influence of genetic selection or differences in other characteristics between groups cannot be excluded.

        • High-Intensity Interval Training Improves Left Ventricular Contractile Function

        ——描述主要发现
        —— Typically, the exercise training effect on cardiac function is assessed by M-mode in echocardiography, which only displays the size of ventricular cavity, myocardial thickness, the integrity of interventricular septum, and the motion of ventricular wall at rest (8). The present study further contributes to a greater understanding of LV mechanical responses to various exercise regimens using stress echocardiography. In summary, HIIT for 6 wk induces eccentric myocardial hypertrophy, enhances myocardial performance, and reduces peak torsion to reduce energy consumption for myocardial contraction, thereby improving LV contractile function. On the other hand, this exercise regimen also improves diastolic function by increasing the Vp and the E/A ratio as well as reducing the time to reach peak untwisting velocity, consequently increasing SV. Although MICT modestly elevates myocardial contractility, cardiac diastolic function remains unchanged after this exercise intervention. The present findings provide a new insight into the superior effects of HIIT on LV mechanics during exercise by simultaneously increasing contractile and diastolic functions and may have important implications for exercise training in cardiac rehabilitation.

        • High-Intensity Interval Training to Maximize Cardiac Benefits of Exercise Training?

        —— 细胞水平上,心肌肥大幅度取决于运动强度
        ——High-intensity exercise training at 85%Y90% of V? O2max induces a hypertrophic response in the cardiomyocytes that is observable already after a few weeks and reaches a plateau after approximately 2 months (16,17,31). The magnitude of cardiomyocyte hypertrophy depends on the intensity of exercise because high-intensity exercise training induced a substantially larger response than moderate intensity: 14% versus 5% longer cells, respectively (16).

        • High-Intensity Interval Training Improves Left Ventricular Contractile Function

        ——解释MICT没有引起LVmass增加:训练量小
        —— On the other hand, we speculate that the exercise volume of MICT in this study might be too low to exert any positive effects on cardiac hemodynamic adaption in these subjects. The majority of the positive MICT studies applied the exercise training at least 5 d穡k-1 up to six times daily for a period of at least 12 wk (37). As in numerous other investigations, a limitation of this study is that the subjects tended to be young and healthy. Thus, additional clinical evidence is required to extrapolate the present results to patients with abnormal cardiovascular systems, such as patients with myocardial ischemia or heart failure.

        • Magnitude, Reproducibility, and Association With Baseline Cardiac Function of Cardiac Biomarker Release in Long-Distance Runners Aged >55 Year

        —— 宽的数据范围,适合做相关
        —— The exertional release of NT¨CproBNP was highly associated with its baseline levels. Although this relation may appear obvious, it has never actually been reported previously. This age group may constitute a particularly useful sample for studying this association, because NT¨CproBNP levels showed relatively wide dispersion, including 5 subjects with pathologic levels already at baseline.

      • 引言,背景

        • Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart

        —— 结构与生化的联系 理解很少
        —— While these structural and functional attributes of exercise-induced cardiac remodeling have been thoroughly delineated (3), the biochemical correlates of this process are not yet fully understood.

        —— 训练及伴随的心脏塑性对cTn影响,仍未研究
        ——To date, the vast majority of periexercise cTnT data describe single exercise bouts (23, 27), and thus the potential impact of ET and attendant cardiac remodeling on cTnT has not been examined.

        ——运动心肌塑性的生化特征知之甚少,本研究对此有贡献
        ——At present, the biochemical characteristics of EICR are less comprehensively understood and findings from the current study advance our understanding of this element of cardiac plasticity in several ways.
        ——Longitudinal data with pre- and post-ET measurements confirm prior cross-sectional studies (1, 24, 31) suggesting that EICR does not result in increased NPs under resting conditions. Similarly, our data suggest that cTnT levels, both at rest and after brief bouts of maximal effort exercise, are unaffected by endurance ET. In addition to these confirmatory findings, we now show that endurance ET with corollary EICR results in an attenuated NP response to acute bouts of maximal intensity exercise.

        • Immediate and 24-h post-marathon cardiac troponin T is associated with relative exercise intensity

        —— 与预期相反:不相关
        ——However, contrary to our expectations, baseline echocardiographic and cardiovascular fitness variables were not associated with hs-TNT rise and normalization, except for a small association between LVESD and post-race hs-TNT values, which seems clinically unimportant.

        • Relationship between Post-Exercise Plasma CK Elevation and Muscle Mass Involved in the Exercise

        —-描述不相关
        ——In summary, the results of this study did not find a relationship between the magnitude of post-exercise plasma CK and muscle mass affected by an eccentric exercise. It is quite remarkable that subjects who exercised two arms would have very similar CK responses as those exercising only one arm. It is concluded that the amount of CK increase after exercise does not necessarily indicate the amount of muscle damaged

        • Exercise training and artery function in humans: nonresponse and its relationship to cardiovascular risk factors

        —— 描述相关;
        ——We found that cardiopulmonary fitness improved, and weight, body mass index (BMI), cholesterol, and mean arterial pressure (MAP) decreased after training, while FMD% increased in 76% of subjects (P 0.001).
        —-With the exception of a modest correlation with total cholesterol (r  0.243, P 0.01), changes in traditional cardiovascular risk factors were not significantly related to changes in FMD% (P  0.05).
        ——exercise training-induced change in FMD% did not correlate with changes in traditional cardiovascular risk factors, indicating that some cardioprotective effects of exercise training are independent of improvement in risk factors.

        • Immediate and 24-h post-marathon cardiac troponin T is associated with relative exercise intensity

        —— 解释为何不相关
        ——The absence of a relationship between post-race hs-TNT levels and self-reported training history was also observed by (Kleiven et al. 2019). However, this observation differs from results of other previous studies (Fortescue et al. 2007; Kosowski et al. 2019; Mehta et al. 2012; Neilan et al. 2006), where cardiac troponin release was inversely associated with training experience and weekly training mileage. Our sample was maybe more homogeneous in relation to training status compared to the previous studies, because of our narrow inclusion criteria. This fact could explain why no relationship was identified between post-race hs-TNT values and self-reported training history. On the other hand, the lack of any association between post-race hs-TNT levels and baseline CPET variables (i.e., VO2max, peak speed and speed attained at VT2) concurs with previous studies (Kosowski et al. 2019; Richardson et al. 2018; Trivax et al. 2010). Similarly, our results also coincide with the preceding investigations, which showed a lack of correlation between echocardiographic measures and hs-TNT release after exercise (Donaldson et al. 2019; Kosowski et al. 2019; Paana et al. 2019)

        • High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014

        ——解释机制
        ——Although the performance-enhancing effects of nicotine are unlikely to explain the differences observed, higher myocardial perfusion as a consequence of nicotine use could be a possible mechanism for lower circulating concentrations of cTn in snus users.
        ——Associations between smoking and improved short-term outcomes have been described for several cardiovascular disorders.30¨C32 The mechanisms underlying the ¡°smokers¡¯ paradox¡± are unknown, but a possible explanation could be that tobacco protects myocytes by preconditioning.31,32 Whether this apparently cardioprotective effect of smoking also holds true for snus is unknown. Furthermore, if the smokers¡¯paradox is the result of the biological effects of tobacco or could be explained by selection and/or unmeasured bias is an ongoing discussion.30,33

        • Cardiac Troponin T in Healthy Full‑Term Infants

        —— 原因不十分清楚,几种可能的解释
        —— What causes the transient rise of cTnT in newborn infants is not fully understood. One possible explanation could be the transient hypoxia related to delivery, in combination with the physiological circulatory adaptation starting after birth. The circulatory adaptation continues during the first days of life which might explain the elevated values of cTnT seen several days after delivery. It is not clarified at what time point cTnT reaches its highest levels postnatally nor when it equals adult reference values.

        • High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014

        ——本研究的贡献
        ——In the current study, we add to the existing knowledge by providing data on the associations between snus tobacco and the exercise-induced troponin response. Our results indicate that substances in tobacco may modulate the acute release and/or degradation of cTn in the exercise-induced release setting.

        • Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart

        —— 训练 心肌塑性 生化联系 细胞机制
        —— Remodeling in our cohort was characterized by an ~7% increase in LV wall thickness but only a 3% increase in LV chamber radius, a pattern that does not only preserve, but actually reduces cardiac wall stress during maximal effort exercise. This observation underscores the true adaptive nature of EICR and for the first time provides objective biochemical correlates. Complementary underlying cellular mechanisms including downregulation of NP synthesis and/or attenuated release in response to pressure/volume mechanotransduction are likely responsible. Future work will be required to define the precise cellular pathways that underlie ET-induced downregulation of the NP response to acute bouts of exercise.

        • The effects of exercise on cardiovascular biomarkers in patients with chronic heart failure

        —— 不是一个可靠的指标
        ——Although inflammation and myonecrosis play a central role in the pathogenesis of chronic HF, only a handful of studies have reported on changes in hs-CRP and cTnT with exercise in patients. These studies have not included patients with established HF; to our knowledge, this is the first look at the effects of exercising training on serial hsCRP and cTnT levels in this patient population.19-22 Our results suggest that serial measurements of these biomarkers may not be reliable surrogates for any health benefits of physical activity in this patient population.

        • The effects of exercise on cardiovascular biomarkers in patients with chronic heart failure

        —— 我们的结果有临床意义
        —— We believe that these data have important clinical implications as biomarker-guided therapy becomes more routine in the management of chronic HF, and effects of key therapeutic interventions on serial biomarker levels require clarification. Although exercise training has a class 1 recommendation by both the 2012 European Society of Cardiology and 2013 American College of Cardiology/American Heart Association guidelines for the treatment of chronic HF, its effects on serial levels of commonly measured cardiovascular biomarkers are unclear.1,2 This study, an analysis of the definitive trial of exercise training in HF that led to the recommendations above, is the first to have standardized ascertainments of detailed exercise data and serial biomarker measurements on HF patients randomized to exercise interventions versus standard of care and found no meaningful effect of exercise on serial levels.

        ——The most immediate clinical implications of our results relate to the use of exercise to reduce natriuretic peptide levels in patients with chronic HF, a strategy that has been perpetuated in the literature as accepted wisdom.1,5

      • *Evidence of direct cardiac damage following high-intensity exercise in chronic energy restriction

        —- 这个信息有何用?
        —-A greater understanding would be vitally important, not only for those working with females competing in so called “lean sports”, but also for the general exercising population and matters relating to public health. If a deleterious link between energy deficit and high-intensity exercise was identified, individuals who may be “at risk” could be identified from the risk stratification model proposed in Fig. 2. Subsequently, the most appropriate intervention for the individual could be initiated.
        —- As such the use of cutoff thresholds for normal healthy populations may need to be reconsidered in lean and energy deficient populations, particularly for use in long-term risk stratification.

        • High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population

        —- 高敏测试:cTn出现在无症状的人群,危险分层、一次测试
        —-The current commercially available hs-cTn assays provide cTn detection in a significant proportion of asymptomatic individuals, thus allowing its consideration for CV risk stratification in the general population based on a single measurement. Risk stratification in asymptomatic population concerns the range of cTn values between the lower limit of detection and the 99th percentile of normal and not higher values that are indicative of disease.31

        • High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population

        —- cTn 是个有价值的危险分层的指标
        —-The accumulated bulk of evidence shows that hs-cTn predicts future CV events, including mortality, MI, and HF (Table 4). At the same time, the biomarker is responsive to preventive interventions such as statin therapy, weight control or increased physical activity, while its values parallel CV risk modification. In addition, the use of hs-cTn in this setting improves risk prediction when added to well-established prognosticators, a fact that may be partly related to its cardiac specificity. The incremental prognostic value of hs-cTn may help addressing the residual CV risk not covered by established prognostic markers and tools. Evidence shows that this approach may further be cost-effective.52

        • Prevalence and determinants of troponin T elevation in the general population

        —-微小的升高
        —-Cardiac troponins are increasingly being measured in patients without typical symptoms of ischemic chest pain, and physicians struggle to interpret troponin elevation in these settings, especially when levels are only minimally elevated. In part, this difficulty arises because little is known about the frequency and clinical correlates of troponin elevation in the ambulatory setting. We measured cardiac troponin T (cTnT) in a large population sample from Dallas, Tex, and identified that 0.7% of adult subjects had an elevated cTnT (0.01 g/L). cTnT elevation was associated with a high-risk cardiovascular profile, even when levels were only minimally elevated (0.01 to 0.03 g/L).

        • Cardiac troponin I is released following high-intensity short-duration exercise in healthy humans

        —— 习惯规律运动者可能会使安静态cTn增加,干扰危险分层,特别是在高危人群
        —— Accordingly, it is highly likely that a large percentage of the population regularly engage in exercise that will stimulate a physiological release of cTn. Whilst not problematic in the healthy population, an exercise associated release of cTn may become diagnostically important if an individual is admitted to hospital with the suspected acute coronary syndrome. The current drive for highly sensitive cTn assays [6] will likely lead to increased detection of exercise-associated increases in cTn. Moreover, the very low background concentrations of cTn shown in the normal healthy population [7] may also result in cTn positive samples using highly sensitive assays. Accordingly, before the wholesale adoption of highly sensitive assays occurs it is important that appropriate clinical guidelines are established that consider both normal circulating levels and exercise associated elevations in cTn.

      • 当人们已知到cTn检测前应避免剧烈运动时,我们的研究进一步增加了知识:处于训练期间的人即便休息了48小时,仍可影响cTn的检测。

        • High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014

        ——提示未来的研究
        ——The current results, combined with data from prior reports observing an inverse association between cigarette smoking and concentrations of cTn, suggest that the effect is real and underscore the need for further experimental research exploring the potential underlying mechanisms for this apparently paradoxical phenomenon.

        • High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population

        —- 机制并未完全理解;解决机制有助于确定预防干预的新靶点。
        —- The predominate trigger and exact mechanisms of cTnT/I release from cardiomyocytes in asymptomatic individuals are incompletely understood.58 Elucidation of the underlying pathophysiology by studies addressing sensitive indices of CV function, besides improving our understanding, may further contribute to the identification of novel targets for preventive interventions.

        • High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population

        —- 今后的工作,谁应该、5隔多久、用什么干预措施?
        —- Several issues described above need to be addressed by prospective randomized studies that would translate the important prognostic features of hs-cTn into a comprehensive strategy, defining who should be screened, how often should monitoring occur, and what should be the interventions in people with increased risk. The education of the wide spectrum of physicians involved in primary prevention, including cardiologists, general practitioners, family doctors, internists, and other specialists, is required to raise awareness of this novel feature of hs-cTn and facilitate its future clinical endorsement.

        • High-sensitivity cardiac troponin T in young, healthy adults undergoing non-cardiac surgery

        —- 需解决。。
        —- Thus, additional research is needed to determine how much change in hscTnT can be expected after operation as part of normal physiology vs a truly pathological process. This is of particular importance given the modest changes we observed in our putatively normal patients, with most hscTnT increases at <4 ng litre1.

        • Cardiac Troponin T in Healthy Full‑Term Infants

        —— 仍需解决:时间点
        —— It is not clarified at what time point cTnT reaches its highest levels postnatally nor when it equals adult reference values.
        —— Further studies are warranted to clarify at what time point hs-cTnT reaches its highest levels after birth and when it equals normal adult values.

        • Relationship between Post-Exercise Plasma CK Elevation and Muscle Mass Involved in the Exercise

        —— If a study is carefully designed to eliminate an adaptation effect and an eccentric exercise that has been reported to produce substantial muscle damage is used for an exercise model, a relationship between the amount of increase in CK and damage size may be possible to find.

        • How is cardiac troponin released from injured myocardium?
          —-A limitation of these experiments was that apoptosis was claimed instead of being based on electron microscopy morphological findings only on the basis of standard biochemical methods (i.e. terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling – positive nuclei and immunostaining for active caspase-3), which have also been criticized for lack of sensitivity and specificity for apoptosis.2 Therefore, to overcome this the diagnosis of ‘apoptotic cardiomyocytes’ required that cardiomyocytes stained positive with both biochemical methods. Ideally, however, a morphological workup of the hearts using electron microscopy would have been necessary to undoubtedly prove cardiomyocyte apoptosis and the absence of cardiomyocyte necrosis.2 But this is obviously very labor-intensive and difficult to perform in such kinds of experiments.
        • How is cardiac troponin released from injured myocardium?
          —-The extent to which these alternative mechanisms of cTn release contribute to small hs-cTn elevations which are seen in daily clinical practice still remains to be shown more definitively, but this should be an area of further future investigation.
          这些cTn释放的替代机制在多大程度上导致了小的hs-cTn升高(在日常临床实践中可见)仍有待进一步证实,但这应该是未来进一步研究的一个领域。
        • High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014

        ——概述运动性cTn及意义挑战
        ——提示进一步工作
        ——An increase in concentrations of cTn following intense exercise is commonly observed.2 Activity-related changes in serum enzymes have been known for several decades,18,19 and, in line with these observations, exercise-induced troponin increase has traditionally been considered a benign and physiological phenomenon. However, recent observations demonstrating associations between the magnitude of postexercise troponin response and cardiovascular disease and outcome20,21 challenge this concept. Moreover, it highlights that more detailed information is needed on determinants of the magnitude of transient elevations of cTn following exercise.

      • Second, we acknowledge the potential for limited generalizability. We studied young, healthy rowers, and thus our results may not generalizable to athletes participating in other forms of ET or patients with cardiovascular diseases.

        • Exercise-Induced Cardiac Remodeling Not a Case of One Size Fits All

        ——Second, EICR changes of the right ventricle were not addressed in this study. In comparison to the left ventricle, the right ventricle suffers a disproportionately high afterload during intense exercise because of the relative pressure increase in the pulmonary circulation exceeding that of the systemic circulation.20 In this regard, one might expect the right ventricle to be the seat of the most profound EICR changes and, therefore, should not be neglected. Arbab-Zadeh et al11 demonstrated that with increasing exercise load, there was eccentric hypertrophy of the right ventricle with a relatively constant right ventricular mass to volume ratio throughout training.

        • High-Intensity Interval Training Improves Left Ventricular Contractile Function

        —— 超声测定
        —— Echocardiography. The echocardiography tests were performed 2 d before the pretraining GXT and 2 d after posttraining GXT. All subjects arrived at the testing center at 9:00 AM to eliminate any possible circadian effect and were asked to avoid any medicine, alcohol, and caffeine consumption throughout the experiment duration. The subjects were positioned in a 30 semiupright position oriented in the left semisupine and 60 lateral decubitus position on an echocardiography imaging table (Cardiac Stress Table w/Angio) (20). The parameters of LV mechanics were measured with the Siemens ACUSON SC2000? ultrasound system (Siemens Medical Solutions USA Inc., Mountain View, CA) using the 4V1c probe (4.5 MHz). This study used one dedicated investigator to perform the collection of echocardiographic data. The data collector was isolated from the data analytic specialist. Moreover, both data collector and analytic specialist were blinded to know the group assignment (HIIT, MICT, or CTL) or experimental time point (preintervention or postintervention) in each subject throughout the period of study. Cardiac images were acquired by 2D and Doppler echocardiography from the parasternal and apical windows (20). The subjects maintained regular breathing patterns, and images were not captured during a breath-hold at end-expiration. M-mode images were used to determine the LV wall and cavity dimensions at end-systole and end-diastole from a parasternal long axis view. Measurements of LV mass and the short fraction index were automatically derived using standard equations. LV ejection fraction (LVEF) was determined using the modified Simpson’s method from the apical four-chamber views. Analysis of Doppler pulsed wave was performed to determine diastolic transmitral blood flow velocities for peak early (E) and late (A) fillings, the ratio of E wave to A wave (E/A), and early diastolic propagation velocity (Vp). The E/A ratio and Vp are sensitive indicators of LV diastolic function (21,22). Higher E/A ratio or Vp reflects that rapid ventricular relaxation promotes a faster influx of blood into the ventricle (21,22). All data were recorded and averaged three times

        • Metabolic syndrome is associated to high-sensitivity cardiac troponin T elevation

        —- 研究有限;不一致;本研究的优势:
        —-Data regarding the association between highly sensitive troponin and MetS are limited. In both children and adults, there is disagreement on whether obesity per se or metabolic abnormalities are the cause of increased hs-TnT (Pervanidou et al. 2013, Zeng et al. 2016). In adults, reports from a relatively small sample in Japan found no significant association between MetS and hs-TnT (Hitsumoto and Shirai 2015). However, recent evidence from a sub-analysis of the ARIC (Atherosclerosis Risk in Communities) study showed a significant association between MetS and hs-TnT (Pokharel et al. 2017). Our results in a relatively large cohort are in line with those of the ARIC sub-analysis. In addition, the observed association between male gender and hs-TnT concur with the ARIC sub-analysis and a large recent meta-analysis including 154,052 participants assessing predictors for hs-Tn elevation (Pokharel et al. 2017, Willeit et al. 2017).

        • High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population

        —- cTnT阳性率。
        —- Detectability rates differ among assays. In the Generation Scotland Scottish Family Health Study on 19501 individuals, hs-cTnI and hscTnT were detectable in 74.8% and 53.3% of participants, respectively.33 Similarly, in a meta-analysis of 28 trials involving a total of 154 052 individuals, the pooled detectability rates were 82.6% for hscTnI and 69.7% for hs-cTnT.34

        • Impact of moderate physical activity on the longitudinal trajectory of a cardiac specific biomarker of injury: Results from a randomized pilot study of exercise intervention

        ——非常小的运动量,急性影响cTn的可能性降低
        —-Furthermore, the intensity of the physical activity intervention arm was moderate, as suggested by the achieved physical activity of 135minutes per week in this group, lower than the consensus guideline recommendation of 150minutes weekly.16

      • *Traditional and new candidate cardiac biomarkers assessed before, early, and late after half marathon in trained subjects

        —- 对训练的适应
        —- Of interest, the suppressed resting concentration of AAT in our athletes, in agree with the unique previous results obtained in professional cyclists, could provide insights on how body adapt to regular training (Semple et al. 2006). In fact, low concentration of CRP and other proinflammatory proteins has been repeatedly found in many types of athletes (Semple et al. 2006; Mattusch et al. 2000; Tomaszewski et al. 2004). This result, associated with the anti-inflammatory nature of exercise itself, evidences the uselessness of antiinflammatory proteins to be upregulated in trained athletes. The situation can change for other conditions, such as in HF, where α-1 proteins, of which AAT is the major component, increase (Lubrano et al. 2017). In this case, it is plausible that the increase of AAT suppresses the negative effects of elastase production and indirectly inhibits complement activation, that is an anti-inflammatory effect. Since it is the first observation in this setting, this finding must be confirmed in further studies.

      • *Evidence of direct cardiac damage following highintensity exercise in chronic energy restriction

        —-机制不清
        ——The main findings of this case report are that low-energy availability may be associated with augmented cTnI release following anaerobic exercise. Whether the appearance of clinically raised levels of cTnI in this work is because of pathological mechanisms, or, a temporary and benign physiological response like that in endurance exercise, or an isolated individual response is not certain.

        • Association of Troponin T Detected With a Highly Sensitive Assay and Cardiac Structure and Mortality Risk in the General Population

        —— 解释cTnT增加
        ——One hypothesis is that an upward trajectory of levels of hs-cTnT may represent a process of increased myocyte apoptosis with subsequent replacement with fibrosis and increased cardiac stiffness. Recent evidence from magnetic resonance imaging shows a relatively high (17%; 95% CI: 14% to 19%) prevalence of unrecognized myocardial infarctions in a cohort of older adults (28). Therefore, occult myocardial infarction could be 1 potential mechanism to account for increased hscTnT levels. Another hypothesis is that an upward trajectory of NT-proBNP levels may represent subtle increases in fluid and sodium retention from both cardiac and noncardiac mechanisms increasing a vulnerability to symptomatic HF. Inclusion of both an increasing hs-cTnT level and NTproBNP level may identify those most likely to have a cardiac-specific mechanism for increasing fluid retention and potentially identify those still asymptomatic individuals to be targeted with a specific therapy, such as aldosterone antagonists, that might reduce cardiac fibrosis and fluid retention.

      • -Nosaka K, Clarkson PM. Relationship between post-exercise plasma CK elevation and muscle mass involved in the exercise. Int J Sports Med. 1992
        -
        -
        Although the mechanism underlying muscle protein release from damaged muscle cells is not clear, it is generally believed that an abnormality or disturbance of the plasma membrane is necessary (12,22,23). In fact, plasma membrane lesions have been shown in dystrophic muscle fibers, and patients with muscular dystrophy show elevated levels of CK in the blood (6,23). Eccentric exercise is also thought to produce plasma membrane damage (1,9). This damage could induce a loss of intracellular calcium homeostasis and trigger a sequence of events leading to cell necrosis (1,8,25). Either plasma membrane damage or muscle cell necrosis, or a combination of the two would be associated with the large CK increase after eccentric exercise.

      • physiological cardiomyocyte renewal

        • Measurement of circulating concentrations of cardiac troponin I and T in healthy subjects: a tool for monitoring myocardial tissue renewal?
      • 凋亡

        • How is cardiac troponin released from injured myocardium?
          ——Cardiomyocytes might die also because of enhanced apoptosis. The extent to which these alternative mechanisms of cTn release contribute to small hs-cTn elevations which are seen in daily clinical practice still remains to be shown more definitively, but this should be an area of further future investigation
      • 心肌细胞更新

        • Measurement of circulating concentrations of cardiac troponin I and T in healthy subjects: a tool for monitoring myocardial tissue renewal?
          ——-hypothesis that cardiac troponins can be released from cardiomyocytes, even in healthy adult subjects as a result of a process related to ‘‘physiological renewal’’ of the human myocardium and possibly enhanced by physical exercise or aging.

        ——年轻人更新率更高
        The results of this study suggested that cardiomyocytes can renew themselves, with a gradual decrease in annual turnover from 1% at the age of 25 years to 0.45% at the age of 75 years, with, on the whole, fewer than 50% of cardiomyocytes exchanged during a normal life span (26).

        • The effects of exercise on cardiovascular biomarkers in patients with chronic heart failure

        —— 我们的结果 挑战了一个假设:我们并没有发现。。。尽管结构化的系统训练
        ——Findings from this study challenge the hypothesis that exercise training improves commonly evaluated cardiovascular biomarkers in patients with chronic HF. We found that plasma levels of NT-proBNP, hs-CRP, or cTnT did not significantly improve at 3 months despite a structured exercise training program, even after accounting for baseline biomarker levels. Although patients who tended to exercise more had lower levels of NT-proBNP and hsCRP and decreased risk of adverse clinic outcomes, volume of exercise did not influence serial levels. Only decreases in NT-proBNP translated to improvements in functional capacity and reductions in risk of clinical outcomes.

        • The effect of exercise training on the course of cardiac troponin T and I levels: three independent training studies

        ——解释结果:不能排除…. 但…;可能的限制,,,但。。阻力训练不是有效的手段,但耐力训练也是阴性
        ——Although the absolute number of subjects in these training studies are relatively low, all studies afforded at least 90% power to detect a 10% reduction of cardiac troponin over time. We cannot exclude the possibility that training confers a smaller effect on the course of troponin levels that goes by undetected in the present study, but we feel that (much) smaller changes than specified in our power calculation would comprise limited clinical relevance. A possible limitation of our study relates to the type of exercise training intervention, comprising mostly resistance-type exercise. However the subjects’ physical state precluded (intense) endurance training. Despite the physical and metabolic improvements found in our studies18–20,22,23, a valid question may be whether resistance-type exercise training is the most appropriate type of training to generate a favorable effect on cardiac troponin concentrations. In this respect the results of a recently conducted cardio-based exercise training intervention study in heart failure patients are interesting. Similar to our studies, no favorable effect was found of a supervised endurance exercise training program on cardiac troponin T levels15.

        • Effects of a low-volume aerobic-type interval exercise on VO2max and cardiac mass

        —— 训练时间频率不足,造成MCT对LVmass无影响。
        ——Cardiac MRI revealed that an 8-wk (five times per week), 40-min, traditional, moderate-intensity continuous exercise (the CAT) had no significant impact on myocardial mass. Two previous studies (19,30) using the MRI method showed increases of 8.2% and 5.5% in LV mass after 3 months of endurance training (bicycle ergometer and jogging, respectively). Another MRI study by Spence et al. (31) also showed a significant 8.3% increase in LV mass after 6 months of exercise training, although their exercise protocol included walking, running, hill running, and short intervals. Compared with these studies (19,30,31), our CAT exercise period (8 wk) may have been relatively short for detecting a significant increase in LV mass. Conversely, although the exercise volumes of interval exercises in our study were small, LV mass increased with both sprint- and aerobic-type interval training. Moreover, percentage changes in SV and HR were significant in both SIT and HIAT (Fig. 3).

        • Low-volume, high-intensity, aerobic interval exercise for sedentary adults: VO₂max, cardiac mass, and heart rate recovery

        —— 描述不相关,意味着什么?
        ———-In the present study, we found no significant correlations between Hrr values and cardiac MrI values (data not shown), i.e., the study did not detect any associations between changes in Hrr and cardiac functions induced by exercise training.

        • Cardiac Troponin T in Healthy Full‑Term Infants

        —— 以前的研究,仍存在的空白
        —— Several studies have investigated cTnT values in infants after admission for neonatal care [3¨C5, 10¨C24]. Only a limited number of studies have determined cTnT values primarily in healthy full-term infants [1, 2, 25¨C28]. All but one of these studies have been performed before the introduction of hs-cTnT assays [2] and a considerable proportion of cTnT values were even below the detection limit [1, 25]. Cardiac troponin T has in most cases been determined either in cord blood [1, 2, 25, 26, 28] or in peripheral blood [3, 11¨C13, 17¨C19, 21, 29]. Only a few studies have done sequential measurements of cTnT, and primarily in asphyxiated or premature infants [5, 10, 16]. We aimed to investigate hs-cTnT values in cord blood and during the first week of age, in healthy full-term infants born either after spontaneous onset of delivery, or after planned caesarean section (CS). We hypothesized that hs-cTnT would be elevated already in cord blood, compared with the adult upper reference limit, and that it would further increase over the first 2¨C5 days of age. We finally hypothesized that hs-cTnT values would be higher in infants born after vaginal delivery compared with infants born after planned CS

        • Predictors of cardiac troponin release after a marathon

        —- 支持、与不支持的研究,相关性
        —- We also observed a positive relationship between exercise duration and post-race cTnI levels. Although this finding is in line with some of the recent field and laboratory studies,8,9 others have reported an opposite relationship between post-race cTnI levels and exercise duration.20,23 These latter studies suggest that longer exercise duration is usually related to lower exercise intensity, and consequently to a lower increase in exercise-induced cTnI levels.20,24 In our study, participants did not demonstrate a relation between finish time and exercise intensity (r = 0.11, p = 0.36). Given the homogeneous exercise intensity in our population, participants with longer exercise duration were exposed to higher cardiac stress. The release of exercise-induced cTnI levels in participants with longer exercise duration may therefore relate to the higher cardiac work. However, it must be emphasized that future studies should further examine whether troponin-release after exercise relates to absolute cardiac work, independent of exercise type.

        • Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart

        —— 结果:LVmass+,restingcTnT=, VO2max+
        尽管cTnT=,但仍支持LVmass与cTnT无相关性

        • Impact of an endurance training program on exercise-induced cardiac biomarker release

        —— 讨论 安静值高 讨论相关
        —— We observed higher baseline and peak postexercise values for hs-cTnT after 14 wk of running training, which also differentiated this group from the control cohort. This supports some previous cross-sectional data from athletes of different training status (Legaz-Arrese et al., unpublished observations; and Ref. 24) but does contradict past field-based studies of runners with higher and lower selfreported training volumes (e.g., Ref. 20). The assay precision and method used to quantify the level of training may also be confounding factors in the relationship observed in previous studies. In the largest case series data in marathoners, Fortescue et al. (5) noted that the runners with less prior experience in marathon running were more likely to have cTnT increases. They also found no relationship between race time and the increase in cTnT, suggesting that the number of previous marathons may not be the most appropriate way to quantify the current level of training. Furthermore, the authors indicated no significant relationship between the release of cTnT and average training pace or average miles run per week during the last 3 mo. In the same direction, a multiple regression analysis demonstrated that marathon experience was a significant predictor of postmarathon hs-cTnT (19). Once again, the authors did not establish a relationship between marathon time and the release of hs-cTnT and did not gather other data on the level of training of the athletes. The association observed by Nie et al. (21) and Tian et al. (39) between the number of years of training and cTnT or cTnI release after a half-marathon in adolescent subjects was weak and could have been influenced by the maturity status of the adolescents. Moreover, in neither of these studies did the authors observe a relationship for other indicators of the level of training, such as weekly training distance. Finally, using a prospective study design, Mehta et al. (15) revealed that average miles run per week in the last 3 yr (an indicator of previous training experience) was negatively associated with postmarathon cTnI release. No association, however, was observed for the current training status (miles run per week in the last 4 mo) or for race time

        • Relation of Lifestyle Factors and Life’s Simple 7 Score to Temporal Reduction in Troponin Levels Measured by a High-Sensitivity Assay (from the Atherosclerosis Risk in Communities Study)

        ——我们没有发现,cTn与LVmass的联系;可能的解释是:
        ——In the current study, we did not find an association between healthy diet score and reversal of subclinical myocardial damage. One possible explanation is that the cardioprotective effects of a healthy diet are not realized in the short, 6-year follow-up of our study. Moreover, we carried forward the visit 1 dietary information, which may not best reflect diet at visit 2. The 5 components of the healthy diet score of the AHA LS7 and the thresholds used to dichotomize the population as meeting criteria may not fully represent diet quality that are relevant for cardiovascular health. Additionally, the food frequency questionnaire, which was administered in the ARIC study, is not the ideal dietary assessment instrument for quantifying absolute intake of sodium.24 We also did not find an association between moderate alcohol consumption and incident undetectable hs-cTnT.

        —-解释为何大样本研究发现了相关
        —-Our finding showed that current smoking may have a “protective,” although nonsignificant, effect on subclinical myocardial damage in our main analysis; we observed a strong association between current smoking and risk of all-cause mortality during our study follow-up (Supplementary Table S2), suggesting that the observed inverse association between current smoking and hs-cTnT may be influenced by survival bias or reverse causality. This inverse association is consistent with several previous studies.6,25 It has been postulated that smoking may reduce cardiac myocyte turnover and immune mediated myocardial remodeling, reflected in lower levels of circulating troponins.26 Additionally, given that smoking is associated with lower BMI,27 our counterintuitive results may be in part mediated by the impact of smoking on reduced BMI, which is associated with decreased likelihood of incident myocardial damage.

        • Sex influence on myocardial function with exercise in adolescents

        —- 可能受到了衰老及心脏病理的影响
        —- Previous investigations in middle- to older age populations may have been influenced by the aging process itself as well as occult coronary disease. This study assessed myocardial performance in an earlier phase of sexual maturity to eliminate such influences.

        • Prevalence and determinants of troponin T elevation in the general population

        —- LVmass 病理性心肌肥大 导致cTn升高的,可能机制
        —- Troponin elevation seen with LVH may be the result of a supply/demand mismatch whereby hypertrophied myocytes physically impair adequate endocardial
        tissue perfusion.36

        • Association of novel biomarkers of cardiovascular stress with left ventricular hypertrophy and dysfunction: implications for screening

        —— 年龄增加血压增加,三分之一的人并不知道血压高、血压高引起LVH、病理性LVH?
        ——Given the high prevalence of LVH in the general population (20% to 25%),11,12 and especially in the MI population (50%),27 it is of great importance to know whether LV mass affects the systemic release of biomarkers after an AMI. Notably, stratification according to hypertension—the most frequent cause of LVH—may be insufficient to control the effect of LV mass on biomarker release, given that approximately one-third of patients with hypertension are unaware that they are hypertensive.28

        • Association of novel biomarkers of cardiovascular stress with left ventricular hypertrophy and dysfunction: implications for screening

        —— 肥大的心肌释放了更多的cTnI, 但肥大并不影响CK释放量;直觉推测认为心肌细胞cTn含量会随着心肌肥大而增加,因为cTn随着心肌细胞收缩单位和相关收缩蛋白含量普遍增加而增加。
        ——Our analysis of total CK and cTnI showed that whereas hypertrophied hearts release more cTnI than control hearts upon AMI, hypertrophy does not affect total CK release. The CK system is important for intracellular energy production and utilization and is abundantly present in tissues with high metabolic demand. There are 4 electrophoretically distinct CK isoenzymes—BB, MB, MM, and the mitochondrial forms (mi-CK)—with CK-MB predominating in the adult heart.29 Animal models of LVH consistently show that hypertrophic cardiomyocytes switch to a fetal CK isoenzyme pattern, increasing expression of CK-MB and CK-BB at the expense of reduced expression of CK-MM and mi-CK in order to increase energy yield; these changes balance out so that total CK levels in the hypertrophied myocardium are unaltered.30–35 In contrast, it is intuitive to argue that cardiomyocyte content of troponin would increase with hypertrophy as part of the general increase in cardiomyocyte content of contractile units and associated contractile proteins. Thus, in the setting of LVH, the release of troponins will be disproportionally high after STEMI, whereas total CK release will not be affected.

        • Metabolic syndrome is associated to high-sensitivity cardiac troponin T elevation

        —- 本研究支持…观点,并进一步有贡献
        —-The findings of the ARIC sub-analysis suggest that hs-TnT testing can further refine risk stratification in patients with MetS. Our results corroborate this concept in that it establishes not only an association between Mets and hs-Tn but suggests a continuous relation between the metabolic burden (i.e. the number of MetS components) and hs-TnT in asymptomatic subjects.

        • Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart

        —— 结论、总结、贡献
        —— In summary, rowing-based ET and corollary EICR appear to result in an attenuated NP response to maximal effort exercise. While mechanisms remain speculative, our data suggest that this occurs as a function of disproportionally higher ventricular wall thickening compared with chamber dilation. In aggregate, these observations advance our understanding of the interplay between structural and biochemical adaptations that underlie the cardiovascular response to ET.

        • Association of novel biomarkers of cardiovascular stress with left ventricular hypertrophy and dysfunction: implications for screening

        —- 为何研究混杂因素,为何LVH要观察
        —- The more specific cardiac troponins were introduced later and are increasingly used. Peak and AUC of total CK and cTnI have been shown to correlate well with IS measured by goldstandard techniques. Owing to their cardiac specificity, troponins have become the reference biomarker for estimating IS and thus for predicting long-term clinical outcomes after STEMI,4,24 and, consequently, many experimental studies and clinical trials use cardiac troponins as the primary outcome measure.8,25,26 It is therefore important to identify confounders that affect the release and quantification of cardiac troponins. Given the high prevalence of LVH in the general population (20% to 25%),11,12 and especially in the MI population (50%),27 it is of great importance to know whether LV mass affects the systemic release of biomarkers after an AMI.

        • High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population

        —- cTn危险分层的目标人群:年轻人 获益大
        —-Given the fact that management strategies at the two ends of the CV risk spectrum are rather clear, it could be argued that youngto middle-aged individuals with low-moderate CV risk, according to existing screening tools, may benefit more from additional stratification tools. In the case of ESC-SCORE, this population corresponds to individuals with an estimated 10-year risk of fatal CV disease of 1–5%.19 This low-moderate 10-year risk may be translated into a high lifetime risk. Targeting these individuals with appropriate preventive interventions along with closer follow-up could prevent their progression to a higher risk group.18

        • Association of Novel Biomarkers of Cardiovascular Stress With Left Ventricular Hypertrophy and Dysfunction: Implications for Screening

        —— 当运动训练时,作为普查指标将面临挑战, 仍需大样本的实验验证我们的结果
        ——However, the clinical significance of the modest NRI values remains unclear, thereby rendering it challenging to advocate the use of these novel biomarkers for screening purposes in clinical practice. Additional studies of larger multi-ethnic cohorts are warranted to confirm our results and further investigations are needed to elucidate the clinical significance of modest NRI values (which may be statistically significant).

        • High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population

        —- 排除运动的干扰
        —-The concentration of hs-cTn can further be increased by physical exercise or extra-cardiac conditions. Simple measures to address these issuescould be to avoid hs-cTn testing after exercise or during disease, to confirm levels by repeated measurements and to assess longitudinal changes.?

        • Physical activity - an important preanalytical variable

        —- 运动 训练,影响 化验结果的误解;戒除运动48小时
        —- It is hence noteworthy that test results that fall outside the conventional reference ranges in athletes not only may reflect the presence of a given disease, but may frequently mirror an adaptation to regular training or changes that have occurred during and/or following strenuous exercise, and which should be clearly acknowledged to prevent misinterpretation of laboratory data.
        —- Accordingly, the values of some biomarkers in physically active subjects should be cautiously interpreted, since their results may fall outside the conventional reference ranges, reflecting an adaptation to regular training or changes that have occurred during and/or following strenuous exercise, rather than the presence of a given disease.

        • Patients with certain elevated or decreased analytes and uncertain findings should therefore be asked whether they had been physically active around the time when the test was taken or maybe regularly physical active. Alternatively, the abstention from physical exercise 48 h before blood sampling should be considered.
        • Mental Stress, Exercise, and Other Determinants of Elevation in High-Sensitivity Troponin Levels: A Call for Standardization of Laboratory Protocols

        —— 众多的影响安静cTn的因素,增加了复杂性。测试标准化
        ——There is a growing understanding of the multifactorial determinants of hs-cTnI elevations. As Hammadah et al. (14) point out, these determinants include factors such as heart failure, myocarditis, pulmonary embolism, sepsis, and hypertensive crisis. In addition, various cardiac factors appear to increase the risk for observing elevations in hs-cTnI elevations in CAD populations, including reduced left ventricular ejection fraction, resting perfusion defects, reduced exercise capacity, left atrial size, and diastolic function (2,11,17). The multifactorial determinants of troponin elevations adds complexity to the present study due to the heterogenous nature of the study cohort. Among the patients, 31% had a history of prior myocardial infarction and 13% had a history of heart failure. The presence of resting wall motion abnormality, itself, manifested a moderate correlation with hs-cTnI levels in this study, comparable to that noted between ischemia and hs-cTnI levels. As Hammadah et al. (14) noted, resting perfusion defects and inducible ischemia appeared to be synergistic predictors of hs-cTnI elevations.

        —-Hammadah et al. (14) have performed a large-scale study that confirms and extends the results of prior studies that have demonstrated that elevations in resting hs-troponin levels identify patients who are more prone to stress-induced ischemia, during both exercise and mental stress. Conversely, patients with inducible ischemia have higher resting hs-troponin levels. These and other observations further an emerging consensus that elevations of hs-troponin exists along a continuum of precipitants, ranging from the presence and magnitude of a coronary atherosclerotic burden to the induction of ischemia, development of acute coronary syndromes, and occurrence of myocardial infarction. Because the pathophysiological determinants of cTn levels are multifactorial, there is a need to standardize the methods for conducting laboratory investigations into the precipitants and measurements of troponin elevations during exercise- and mental stress testing. Such standardization could lead to an enhanced ability to compare the results emanating from different medical centers and to study causal mechanisms.

        • Cardiac Troponin T in Healthy Full‑Term Infants

        —— 只测量了2次cTn, 在小的窗口
        —— The main limitation of this study was that we only measured hs-cTnT at two occasions and within a rather narrow time span. We were able to show a significant increase in hs-cTnT values during the first days of life, but we still do not know when hs-cTnT reaches its highest levels after birth or at what time point it descends to normal adult values. Furthermore, due to a limited number of infants it was not feasible to investigate whether there was a significant difference in hs-cTnT values between infants born after vaginal delivery and those born after acute CS or vacuum extraction.

        • Exercise-Induced Left Ventricular Remodeling Among Competitive Athletes: A Phasic Phenomenon

        —-超声测试
        ——Cardiac structural measurements were made in accord with current guidelines.17 The LV ejection fraction was calculated using the modified Simpson’s biplane technique. The LV length was measured in the apical 4-chamber view and was defined as the end-diastolic length from the mitral valve hinge point plane to the most distal endocardium at the LV apex. Resting heart rates were obtained from the final loop of each study. Stroke volume was calculated as LV end-diastolic volume?LV end-systolic volume. Cardiac output was calculated as the product of stroke volume and heart rate. To facilitate application of clinical normality cut points,17 LV mass and LV end-diastolic volume were indexed using body surface area as calculated at each study time point. Longitudinal tissue velocities were measured offline from 2D color-coded tissue Doppler images and are reported as the average of 3 consecutive cardiac cycles. Diastolic tissue velocities are an average of medial and lateral values.

        17.Lang RM, Badano LP, Mor-Avi V, Afilalo J, Armstrong A, Ernande L, Flachskampf FA, Foster E, Goldstein SA, Kuznetsova T, Lancellotti P, Muraru D, Picard MH, Rietzschel ER, Rudski L, Spencer KT, Tsang W, Voigt JU. Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2015;28:1–39.e14. doi: 10.1016/ j.echo.2014.10.003

      • *Cardiac Biomarker Release after Endurance Exercise in Male and Female Adults and Adolescents

        —- 对cTnT的讨论
        —- This study confirms that the exercise-induced release of cTn and NT-proBNP is not exclusive to an ultra-endurance effort in adult athletes.5,6,23,24
        —- There is some evidence to suggest that cTn release during prolonged exercise is positively associated with exercise intensity.25,26 Thus, the high intensity shown by our swimmers could explain the release of hs-cTnT.
        —- The percentage of participants exceeding the URL (62%) of hscTnT was comparable with the only previous study with male adult swimmers who performed the same exercise test (64%).23
        —- These results confirmed findings of marked individual variability in the release of hs-cTnT with exercise.6,10 This variability could partly be explained by differences in the %HRmax between the subjects and could be linked to recent findings that suggest that the release of hs-cTnT with exercise is higher in subjects with more training or with better “athletic” status5,6 who are usually capable of maintaining higher %HRmax values for specific durations of effort. This seems the most probable explanation for the absence in some subjects of hs-cTnT increase after exercise.
        —- The %HRmax does not explain all of the variability in the hs-cTnT and high %HRmax values were observed in subjects with negligible release of hs-cTnT and this suggests that some other, currently unknown, factor/process may make participants more or less likely to release cTn in response to exercise.
        —- There was much more consistency in the overall “pattern” or “kinetics” of hs-cTnT throughout the 24hour recovery period. Our data reflect a rapid rise in hscTnT in the early hours of recovery, with most of the subjects reaching a peak at 3 hours, with close to complete recovery to baseline at 24 hours. These observations were consistent between individuals and largely agreed with the few studies reporting detailed hs-cTnT kinetics over 24 hours.6,10,23
        —- Several studies have suggested that the cTn release after endurance exercise might be greater among adolescent athletes compared with adults, possibly because of the immature cardiac muscle of the adolescent.10,12,13,28,29 The results of this study do not support this hypothesis and agree with a previous work in which no differences in cTnI release were observed in a male sample after a basketball match between adolescents and adults.14
        Conversely, in the only other controlled study according to the adolescent-adult condition, the assessment revealed that adolescents runners had a higher mean postexercise value of hs-cTnT, with a greater number of subjects exceeding the peak URL and more time to recovery.10 One possible explanation for these contradictory findings may be associated with differences in the pubertal status of the adolescents between the studies. Adolescents were Tanner stages 3-5 in the current study, 4-5 in basketball players,14 and 2-3 in runners10 suggesting than only early Tanner stage may exert an influence upon hs-cTnT. In runners it was observed that adolescents at Tanner stage 2 had higher peak hs-cTnT than those ofTanner stage 3, although the difference was not statistically significant.10 Ongoing work should determine the causes of and suggest that the high between-subject variability. Instead, our results agree with the study evaluating the runners10 adolescent-adult and pubertal status do not influence NTproBNP release with exercise. This is consistent with our observation that no difference between groups in baseline NTproBNP exists; this strongly explains postexercise NT-proBNP values.

      • *Cardiac Biomarker Release after Endurance Exercise in Male and Female Adults and Adolescents

        —- 对cTnT的讨论
        —- This study confirms that the exercise-induced release of cTn and NT-proBNP is not exclusive to an ultra-endurance effort in adult athletes.5,6,23,24 There is some evidence to suggest that cTn release during prolonged exercise is positively associated with exercise intensity.25,26 Thus, the high intensity shown by our swimmers could explain the release of hs-cTnT. The percentage of participants exceeding the URL (62%) of hscTnT was comparable with the only previous study with male adult swimmers who performed the same exercise test (64%).23 These results confirmed findings of marked individual variability in the release of hs-cTnT with exercise.6,10 This variability could partly be explained by differences in the %HRmax between the subjects and could be linked to recent findings that suggest that the release of hs-cTnT with exercise is higher in subjects with more training or with better “athletic” status5,6 who are usually capable ofmaintaining higher %HRmax values for specific durations of effort. This seems the most probable explanation for the absence in some subjects of hs-cTnT increase after exercise. The %HRmax does not explain all of the variability in the hs-cTnT and high %HRmax values were observed in subjects with negligible release of hs-cTnT and this suggests that some other, currently unknown, factor/process may make participants more or less likely to release cTn in response to exercise. There was much more consistency in the overall “pattern” or “kinetics” of hs-cTnT throughout the 24hour recovery period. Our data reflect a rapid rise in hscTnT in the early hours of recovery, with most of the subjects reaching a peak at 3 hours, with close to complete recovery to baseline at 24 hours. These observations were consistent between individuals and largely agreed with the few studies reporting detailed hs-cTnT kinetics over 24 hours.6,10,23
        —- Several studies have suggested that the cTn release after endurance exercise might be greater among adolescent athletes compared with adults, possibly because ofthe immature cardiac muscle of the adolescent.10,12,13,28,29 The results of this study do not support this hypothesis and agree with a previous work in which no differences in cTnI release were observed in a male sample after a basketball match between adolescents and adults.14
        Conversely, in the only other controlled study according to the adolescent-adult condition, the assessment revealed that adolescents runners had a higher mean postexercise value of hs-cTnT, with a greater number of subjects exceeding the peak URL and more time to recovery.10 One possible explanation for these contradictory findings may be associated with differences in the pubertal status of the adolescents between the studies. Adolescents were Tanner stages 3-5 in the current study, 4-5 in basketball players,14 and 2-3 in runners10 suggesting than only early Tanner stage may exert an influence upon hs-cTnT. In runners it was observed that adolescents at Tanner stage 2 had higher peak hs-cTnT than those ofTanner stage 3, although the difference was not statistically significant.10
        Ongoing work should determine the causes of and suggest that
        the high between-subject variability. Instead, our results agree with the study evaluating the runners10 adolescent-adult and pubertal status do not influence NTproBNP release with exercise. This is consistent with our observation that no difference between groups in baseline NTproBNP exist; this strongly explains postexercise NT-proBNP values.

        • High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014

        ——解释机制
        ——Although the performance-enhancing effects of nicotine are unlikely to explain the differences observed, higher myocardial perfusion as a consequence of nicotine use could be a possible mechanism for lower circulating concentrations of cTn in snus users.
        ——Associations between smoking and improved short-term outcomes have been described for several cardiovascular disorders.30¨C32 The mechanisms underlying the ¡°smokers¡¯ paradox¡± are unknown, but a possible explanation could be that tobacco protects myocytes by preconditioning.31,32 Whether this apparently cardioprotective effect of smoking also holds true for snus is unknown. Furthermore, if the smokers¡¯paradox is the result of the biological effects of tobacco or could be explained by selection and/or unmeasured bias is an ongoing discussion.30,33

        • The effect of exercise training on the course of cardiac troponin T and I levels: three independent training studies

        ——高度的监控训练、带来限制、结果只适合于动机强的人
        ——The supervision during the sessions contributed to the internal validity, but might also have led to increased safety, less adverse events, and a higher motivation among subjects. This may overestimate any beneficial effects of exercise training. Another point regarding the validity of our study is the participant recruitment process and study design. Since participation in the study is associated with a substantial time investment and a relatively high intensity training program, this might have attracted a specific, highly motivated subpopulation. Since our study was conducted in an elderly population we can only speculate about the effects of exercise training on basal cardiac troponin levels in younger subjects who may respond differently on exercise training and demonstrate higher cardiovascular plasticity28. Nevertheless, our study does not provide support for the hypothesis that basal cardiac troponin concentrations are receptive to a prolonged resistance-type exercise training program.

        • The effect of a six-month resistance-type exercise training program on the course of high sensitive cardiac troponin T levels in (pre)frail elderly

        ——解释结果
        ——The finding that the majority of participants had cTnT levels above the 99th percentile confirms our hypothesis that chronically elevated cTnT concentrations are highly prevalent among (pre)frail elderly subjects. However, despite the elevated basal levels of cTnT and the fact that subjects had not previously participated in any structured exercise program, we found no evidence for an effect of a 24-week resistance-type exercise training program on the course of cTnT levels. A possible limitation of our study is that the exercise program was based on resistance-type exercise training, and that a more endurance-type based training may have a greater effect on cTn levels. Another limitation might have been the physical state of the subjects, which precluded a higher training frequency than the biweekly program that was applied in this study. The biweekly schedule was however sufficient to induce substantial improvements of muscle strength and physical performance in this group [8,9]. In conclusion, we demonstrated that prolonged resistance-type exercise training in (pre)frail elderly does not lead to changes in the course of cTnT levels. Future studies will reveal whether more intensive and more prolonged interventions can beneficially affect the course of basal troponin levels over time.

        • Left ventricular function after exercise training in young men

        —— 需要更长的训练才能引起LVmass增加,6个月

        • Low-volume, high-intensity, aerobic interval exercise for sedentary adults: VO₂max, cardiac mass, and heart rate recovery

        —— 描述结果
        ——However, our study also showed that the improved Hrr was not observed in the cAt group even though their V ˙ O2max significantly increased after intervention. Sugawara et al. (2001) demonstrated that Hrr improved after cAt intervention consisting of 8-week, 3–4 days/week, continuous cycling exercise for 60 min at 70 % ˙VO2max in healthy, untrained male subjects. the exercise intensity and duration of our cAt (60–65 % ˙VO2max, 40 min) might be relatively lower for improving Hrr than in their study (Sugawara et al. 2001).

        • Metabolic syndrome is associated to high-sensitivity cardiac troponin T elevation

        —- 研究有限;不一致;本研究的优势:
        —-Data regarding the association between highly sensitive troponin and MetS are limited. In both children and adults, there is disagreement on whether obesity per se or metabolic abnormalities are the cause of increased hs-TnT (Pervanidou et al. 2013, Zeng et al. 2016). In adults, reports from a relatively small sample in Japan found no significant association between MetS and hs-TnT (Hitsumoto and Shirai 2015). However, recent evidence from a sub-analysis of the ARIC (Atherosclerosis Risk in Communities) study showed a significant association between MetS and hs-TnT (Pokharel et al. 2017). Our results in a relatively large cohort are in line with those of the ARIC sub-analysis. In addition, the observed association between male gender and hs-TnT concur with the ARIC sub-analysis and a large recent meta-analysis including 154,052 participants assessing predictors for hs-Tn elevation (Pokharel et al. 2017, Willeit et al. 2017).

        • The effects of exercise on cardiovascular biomarkers in patients with chronic heart failure

        —— 我们的纵向研究,横断研究的缺点:假阳性联系
        ——Lastly, an observational study of 2,933 patients with HF looked at the effects of physical activity on NT-proBNP levels, finding evidence of an inverse relationship between NT-proBNP levels and amount of self-reported physical activity.17,18 Our results confirm the negative correlation between volume of exercise and biomarker levels, but not an association between exercise training and improvements in biomarker levels. This implies that the suggested causal relationship between activity and lower NT-proBNP levels may have resulted from false-positive associations, a common drawback of observational studies.17

        • Physiological and pathological left ventricular hypertrophy of comparable degree is associated with characteristic differences of in vivo hemodynamics

        ——病理性心脏肥大 与 生理性心肌肥大

        • Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart

        —— 生理性心肌肥大与病理性心肌肥大在生化上有区别
        —— Plasma B-type NP levels are typically increased under resting conditions among patients with pathologic ventricular hypertrophy (38). Similarly, resting levels of A-type NPs are driven by LA size in the setting of cardiovascular pathology (7, 10). In contrast, resting levels of B-and A-type NPs are similar among endurance athletes with EICR and healthy normally active controls (1, 24, 31). This suggests that physiologic hypertrophy has different biochemical characteristics than pathologic hypertrophy. Release of NPs during exercise has been well documented in cross-sectional studies across diverse populations with the magnitude of response determined by exercise intensity, exercise duration (23, 31, 37), and the presence or absence of myocardial disease (21, 38). Specifically, exercise duration appears to be a key determinant of BNP release while exercise intensity appears to be the predominant stimulus for ANP release (15)

        • High-Sensitive Cardiac Troponin for Prediction of Clinical Heart Failure

        —— LVH与cTn相关 机制
        ——Hs-cTn elevation may be caused by multiple mechanisms, in addition to myocardial necrosis. These include cardiomyocyte damage from inflammatory cytokines or oxidative stress, apoptosis, increased cell membrane permeability induced by increased stretch or stress with troponin release by injured but still viable cells, fragmentation of altered troponins with release into the circulation of fragments with an affinity for the troponins immunoassays, and production of membranous blebs containing troponins that could release them in the bloodstream.5 Thus, hs-cTn release may not only occur in the setting of myocardial injury related to atherosclerotic coronary heart disease but may be also an expression of other structural phenotypes correlated to HF risk, such as increased LV mass.3

        • Predictors of cardiac troponin release after a marathon

        —- 解释cTn应谨慎
        —- We found that 96% of our marathon athletes demonstrated an increase in cTnI, while 69% of our population exceeded the clinical cut-off value. Since cTnI is recommended as a sensitive and specific marker for cardiac damage in the diagnosis of acute myocardial infarction,3,32 caution should be taken when interpreting postrace cTnI levels. As our participants did not report any symptoms, it is likely that the elevated cTnI levels represent a physiological rather than a pathological response.33 Clinicians should therefore take caution when examining troponin levels without clinical signs indicative of myocardial ischaemia.34 Our study provides some additional clinical insight as we found that lower age and longer exercise duration, albeit weakly, independent predict post-race cTnI levels. Such information is relevant for clinicians as it could improve medical decision making.

        • Prevalence and determinants of troponin T elevation in the general population

        —-临床医生应该意识到:是。。不是急性心梗
        —-Practicing physicians should realize that cTnT elevation is extremely rare among healthy subjects but is relatively common in the presence of cardiac structural and functional abnormalities, diabetes, or renal insufficiency. For example, in the patient with diabetes, moderate renal insufficiency, and left ventricular hypertrophy who presents to the emergency department with atypical chest pain symptoms, minimal troponin elevation may reflect the influence of underlying chronic disease and not be indicative of an acute coronary syndrome event.

      • ——应多点测量;观察点
        In addition to the potential mechanisms described in our paper, it is possible that exercise-induced myocyte turnover influenced conduction pathways. However, we did not take measurements at multiple time points to determine the time course of these outcome measures in response to challenging exercise. Further work is required to elucidate the mechanisms and significance of exercise-induced arrhythmias.

      • Experimental procedure. Subjects rested in a supine position for 10 min before echocardiographic examinations commenced. Examinations were conducted using a Hewlett Packard Sonos 100 ultrasound imaging system with an integrated single-lead ECG. Subjects were examined in the supine position using a 2.5-MHz transducer acoustically coupled with ultrasound transmission gel. Examinations were recorded on Fuji SD E180 high-quality VHS videotape using a Panasonic AG 6200 VHS video recorder. Two-dimensional images (2-D) were obtained from the left parasternal window and used to obtain motion-mode (M-mode) images of the left ventricle. The guidelines of the American Society of Echocardiography (22) were followed for M-mode measurements. Measurements were taken of left ventricular internal dimension at end-diastole (LVIDd, cm) and systole (LVIDs, cm), and of an interventricular septal thickness (ST, cm), posterior wall thickness (PWT, cm), and aortic dimension (cm) at end-diastole. End-diastole was identified as the peak of the R wave on the concurrent ECG, and end-systole as the narrowest point between the interventricular septum and the posterior wall. Left ventricular mass (LVM, g) was calculated from LVIDd, ST, and PWT using the previously validated regression-corrected cube formula of Devereaux and Reichek (5). Ejection fraction percentage was used as an index of contractility and calculated using validated formulae (15). Stroke volume (mL) was calculated as: LVIDd3 LVIDs3. Pulsed wave Doppler measurements were obtained after accurate placement of the sample gate using 2-D imaging from the apical window. Early (E) diastolic inflow, late ventricular inflow (A) after atrial contraction, and systolic outflow envelopes were analyzed for peak flow velocities (vel, cm·s1) and flow integrals (int, cm). Ratios of E to A peak velocities (E:A vel) and integrals (E:A int) were also calculated.

        • High sensitivity cardiac troponins: Can they help in diagnosing myocardial ischaemia?

        —- LVH 影响cTn值
        —- In a recent study evaluating the impact of LVH on troponin release during myocardial infarction, it was estimated that the peak of hs-cTnI overestimates infarct size by approximately 30% in the presence of LVH.26 However, even more critical is the issue of small increments of troponin in patients with chest pain and LVH, given the high prevalence (20–25%) of LVH in the general population26 and the possibility of false-positive diagnoses of myocardial infarction in this setting. In addition, small increments in circulating troponin I27 and T28 have been reported, in patients with LVH, even in the absence of chest pain and any other acute pathology.

        ——机制
        ——Left ventricular hypertrophy enhances troponin release by means of multiple mechanisms. The first cause is simply a greater content of troponin (both structurally bound to contractile apparatus and in a free cytosolic pool, see below) in hypertrophied cardiomyocytes.26 However, the most important mechanism explaining minor and transient increments of troponin in patients without myocardial infarction is probably coronary microvascular dysfunction associated with LVH, which impairs coronary vasodilator reserve and predisposes to stress-induced myocardial ischaemia, also in absence of obstructive CAD.29

      • *Association of Troponin T Detected With a Highly Sensitive Assay and Cardiac Structure and Mortality Risk in the General Population

        —- LVH与其他心血管病相联系
        —- However, our data showing associations with LVH and other cardiac structural abnormalities as well as with mortality among individuals classified at low risk using the FRS suggest that low levels of cTnT may identify subclinical structural heart disease and contributors to cardiovascular disease risk not fully captured by current riskassessment tools. .
        —- 老年人、病理LVH 更高的安静cTnT

      • *An association between volumes of the cardiac chambers and troponin levels in individuals submitted to cardiac coronary computed tomography

        —- 在老年人, 心脏四个腔的容量与cTnI相关

        • Association of Serial Measures of Cardiac Troponin T Using a Sensitive Assay With Incident Heart Failure and Cardiovascular Mortality in Older Adults

        ——老年人群病理性心肌肥大,cTnT升高
        —— Ischemia from known or unknown coronary artery disease must be considered in an older population, but magnetic resonance imaging in another stable older population does not support chronic ischemic heart disease as a predominant etiology linking low levels of troponins with subsequent development of HF.30

      • *Evidence of direct cardiac damage following highintensity exercise in chronic energy restriction

        —- 得知影响因素以及何时测试能显示出适应的效应,有何价值
        —-This information may also assist with clinical interpretations and judgments when conducting risk stratification of individuals presenting with raised cTn levels in the absence of other clinical evidence of acute coronary syndrome.

        • Association of Novel Biomarkers of Cardiovascular Stress With Left Ventricular Hypertrophy and Dysfunction: Implications for Screening

        —— 大样本、cTn与LVH相关;2460 Framingham Study;平均年龄58岁

        • Association of Troponin T Detected With a Highly Sensitive Assay and Cardiac Structure and Mortality Risk in the General Population(#414)

        —— 老年人,cTnT与LVmass相关,病理原因

      {"cards":[{"_id":"41d21070303d1b8b39000210","treeId":"5fd161d2a87c2c03d5d940a9","seq":21966893,"position":0.5,"parentId":null,"content":"* Impact of high-intensity interval and continuous aerobic training on left ventricular mass and circulating cardiac troponin T \n -\n* Increased resting cTnT level induced by exercise training is independent of any changes in left ventricular mass \n-\n* **Exercise training increases resting circulating cardiac troponin T independent of change in left ventricular mass** \nA Randomized Controlled Trial\n\nTherefore, we hypothesized \n*(1) that among sedentary obese females, HIAT and CAT would result in an increase in resting cTnT, compared to pre-training levels,\n(2) the increase of resting cTnT would be greater after HIAT than in CAT, and \n(3) the larger increase in cTnT after HIAT would be associated with a more pronounced increase in left ventricular mass. *"},{"_id":"41d0200d6b30a8b7c2000119","treeId":"5fd161d2a87c2c03d5d940a9","seq":21877549,"position":1,"parentId":"41d21070303d1b8b39000210","content":"# Abstract"},{"_id":"41116a34b08e3c8e9b0000db","treeId":"5fd161d2a87c2c03d5d940a9","seq":21960544,"position":0.5,"parentId":"41d0200d6b30a8b7c2000119","content":"* Exercise training and artery function in humans: nonresponse and its relationship to cardiovascular risk factors\n\n---- 摘要;相关;\n----We found that cardiopulmonary fitness improved, and weight, body mass index (BMI), cholesterol, and mean arterial pressure (MAP) decreased after training, while FMD% increased in 76% of subjects (P 0.001). \n---With the exception of a modest correlation with total cholesterol (r \u0004 \u00050.243, P 0.01), changes in traditional cardiovascular risk factors were not significantly related to changes in FMD% (P \u0006 0.05). \n----exercise training-induced change in FMD% did not correlate with changes in traditional cardiovascular risk factors, indicating that some cardioprotective effects of exercise training are independent of improvement in risk factors."},{"_id":"40ff4f2c4046666ff20000ee","treeId":"5fd161d2a87c2c03d5d940a9","seq":21964444,"position":1,"parentId":"41116a34b08e3c8e9b0000db","content":"* The effect of exercise training on the course of cardiac troponin T and I levels: three independent training studies\n\n----摘要\n----**With the introduction of high-sensitive assays, cardiac troponins became potential biomarkers for risk stratification and prognostic medicine. Observational studies have reported an inverse association between physical activity and basal cardiac troponin levels. However, causality has never been demonstrated. This study investigated whether basal cardiac troponin concentrations are receptive to lifestyle interventions such as exercise training.** Basal high-sensitive cardiac troponin T (cTnT ) and I (cTnI) were monitored in two resistance-type exercise training programs (12-week (study 1) and 24-week (study 2)) in older adults (>/=65 years). In addition, a retrospective analysis for high sensitive troponin I in a 24-week exercise controlled trial in (pre)frail older adults was performed (study 3). In total, 91 subjects were included in the final data analyses. There were no significant changes in cardiac troponin levels over time in study 1 and 2 (study 1: cTnT -0.13 (-0.33-+0.08) ng/L/12-weeks, cTnI -0.10 (-0.33-+0.12) ng/L/12-weeks; study 2: cTnT -1.99 (-4.79-+0.81) ng/L/24-weeks, cTnI -1.59 (-5.70-+2.51) ng/L/24-weeks). Neither was there a significant interaction between training and the course of cardiac troponin in study 3 (p = 0.27). In conclusion, **this study provides no evidence that prolonged resistance-type exercise training can modulate basal cardiac troponin levels.**"},{"_id":"40fe84b30e891323a00000f4","treeId":"5fd161d2a87c2c03d5d940a9","seq":21964557,"position":1,"parentId":"40ff4f2c4046666ff20000ee","content":"* Impact of moderate physical activity on the longitudinal trajectory of a cardiac specific biomarker of injury: Results from a randomized pilot study of exercise intervention\n\n----摘要\n----BACKGROUND: In animal models, physical activity (PA) prevents cardiac myocyte cell death. Data for PA mitigating myocyte injury in humans are limited to observational studies. Using a randomized controlled trial design, we sought to determine if introducing moderate PA to previously sedentary older adults could reduce the trajectory of myocardial injury as measured by the high-sensitive cardiac troponin T (hs-cTnT) assay. \nMETHODS: Participants (age >/=70 years) were assigned to a 1-year intervention of moderate PA or health education control. High-sensitive cTnT was measured at baseline and 1 year in the 307 of 424 subjects who had available stored serum. Changes in hs-cTnT within 1 year were compared between PA and control groups, as were differences in the proportion of subjects with a significant rise in hs-cTnT (prospectively defined as a>50% increase at follow-up from baseline). Moderate to vigorous PA in kcal/wk was estimated with the CHAMPS questionnaire. \nRESULTS: Baseline hs-cTnT levels and PA kcal/wk were similar for both groups. Activity kcal/wk increased in the PA, but not in the control group at 1 year. The median increase in hs-cTnT level from baseline was >3 times larger in the control (0.73 ng/L, interquartile range -0.64 to 2.59) vs the PA group (0.19ng/L, interquartile range -1.10 to 1.93) (P=.02). The proportion with a>50% increase in hs-cTnT was larger in the control group than in the PA group (9.3% vs 5.1%), but this difference was not statistically significant (P=.16). \nCONCLUSIONS: Initiation of moderate PA in sedentary older adults may favorably modify subclinical myocardial injury."},{"_id":"419823766de926ef30000078","treeId":"5fd161d2a87c2c03d5d940a9","seq":21900412,"position":1,"parentId":"41d0200d6b30a8b7c2000119","content":"* Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart\n\n---- 摘要\n---- **Endurance exercise training (ET) stimulates eccentric left ventricular hypertrophy (LVH) with left atrial dilation. To date, the biochemical correlates of exercise-induced cardiac remodeling (EICR) remain incompletely understood. **Collegiate male rowers (n 9) were studied with echocardiography and maximal-effort cardiopulmonary exercise testing (MECPET) before and after 90 days of ET intensification."},{"_id":"4124b46271622f36800000cd","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954643,"position":2,"parentId":"41d0200d6b30a8b7c2000119","content":"cardiac troponin T (cTnT) measured by a highly sensitive assay\ncTnT levels measured with a highly sensitive assay"},{"_id":"4117517dc90d6987c60000d4","treeId":"5fd161d2a87c2c03d5d940a9","seq":21959300,"position":3,"parentId":"41d0200d6b30a8b7c2000119","content":"* Low-volume, high-intensity, aerobic interval exercise for sedentary adults: VO₂max, cardiac mass, and heart rate recovery\n\n---- 摘要\n----Purpose: The aim of this study was to compare the effects of low-volume, **high-intensity aerobic interval training (HAIT)** on maximal oxygen consumption (VO₂max), left ventricular (LV) mass, and heart rate recovery (HRR) with high-volume, **moderate-intensity continuous aerobic training (CAT)** in sedentary adults.\n\nMethods: Twenty-four healthy but sedentary male adults (aged 29.2 ± 7.2 years) participated in an 8-week, 3-day a week, supervised exercise intervention. They were randomly assigned to either HAIT (18 min, 180 kcal per exercise session) or CAT (45 min, 360 kcal). VO₂max, LV mass (3T-MRI), and HRR at 1 min (HRR-1) and 2 min (HRR-2) after maximal exercise were measured pre- and post-intervention.\n\nResults: Changes in VO₂max during the 8-week intervention were significant (P < 0.01) in both groups (HAIT, 8.7 ± 3.2 ml kg(-1) min(-1), 22.4 ± 8.9%; CAT, 5.5 ± 2.8 ml kg(-1) min(-1), 14.7 ± 9.5%), while the VO₂max improvement in HAIT was greater (P = 0.02) than in CAT. **`LV mass in HAIT increased (5.1 ± 8.4 g, 5.7 ± 9.1%, P = 0.05), but not in CAT`** (0.9 ± 7.8 g, 1.1 ± 8.4%, P = 0.71). While changes in HRR-1 were not significant in either group, change in HRR-2 for HAIT (9.5 ± 6.4 bpm, 19.0 ± 16.0%, P < 0.01) was greater (P = 0.03) than for CAT (1.6 ± 10.9 bpm, 3.9 ± 16.2%, P = 0.42)."},{"_id":"41d01b9a6b30a8b7c200011a","treeId":"5fd161d2a87c2c03d5d940a9","seq":21886610,"position":2,"parentId":"41d21070303d1b8b39000210","content":"# Methods"},{"_id":"41bfa481482816e16700004f","treeId":"5fd161d2a87c2c03d5d940a9","seq":21886611,"position":1,"parentId":"41d01b9a6b30a8b7c200011a","content":"## 公用数据"},{"_id":"41bfa36b482816e167000050","treeId":"5fd161d2a87c2c03d5d940a9","seq":21886612,"position":1,"parentId":"41bfa481482816e16700004f","content":"* Familial aggregation of V˙ O2max response to exercise training: results from the HERITAGE Family Study\n-\n* "},{"_id":"41a3191782f21f5e8a000066","treeId":"5fd161d2a87c2c03d5d940a9","seq":21897838,"position":2,"parentId":"41bfa481482816e16700004f","content":"* High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014\n\n---- 大研究中的亚研究\n----This is a substudy of NEEDED (North Sea Race Endurance Exercise Study) 2014. Details of the NEEDED design and the principal results have been previously reported.1 In brief, this is a"},{"_id":"4197f1516de926ef30000079","treeId":"5fd161d2a87c2c03d5d940a9","seq":21900419,"position":3,"parentId":"41bfa481482816e16700004f","content":"The present analysis is a sub-study of the North Sea Race Endurance Exercise Study (NEEDED) 2018. We assessed the change in CAC between the baseline CCTA acquired in either the NEEDED 2013 or 2014 study 7,8 and the follow-up CCTA assessment in 2018 (Figure S1). NEEDED 2018 was approved by the Regional Ethics Committee (REK 2013/550 and REK 2018/63), in compliance with the Declaration of Helsinki. All participants signed informed consent forms prior to enrollment into the studies."},{"_id":"4198ebea6de926ef3000006e","treeId":"5fd161d2a87c2c03d5d940a9","seq":21900214,"position":2,"parentId":"41d01b9a6b30a8b7c200011a","content":"## 研究设计"},{"_id":"4198eb4f6de926ef3000006f","treeId":"5fd161d2a87c2c03d5d940a9","seq":21900217,"position":1,"parentId":"4198ebea6de926ef3000006e","content":"* Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart\n\n---- 研究设计\n---- Study design. A prospective, longitudinal, repeated measures study design was utilized to examine biochemical profiles in human endurance athletes both at rest and during maximal effort exercise. Male student athletes participating in The Harvard Athlete Initiative, an on-going research program designed to address numerous issues relevant to athlete health and exercise physiology, took part in this study during the autumn of 2009. Individuals were considered eligible if they were \u000618 yr old and were newly matriculated, recruited members of the men’s varsity rowing team. Using previously published pre-post LV mass index data from our group derived from a similar population of male rowers undergoing a similar training stimulus (36), we calculated a necessary sample size of n 8 (\u0007 0.05 and \b 0.8) for the current study."},{"_id":"4103be0363376d0ba30000eb","treeId":"5fd161d2a87c2c03d5d940a9","seq":21963052,"position":2,"parentId":"4198ebea6de926ef3000006e","content":" 固定时间测试排除:昼夜节律"},{"_id":"4198e6806de926ef30000070","treeId":"5fd161d2a87c2c03d5d940a9","seq":21900220,"position":3,"parentId":"41d01b9a6b30a8b7c200011a","content":"## 超声测试"},{"_id":"4198e5fa6de926ef30000071","treeId":"5fd161d2a87c2c03d5d940a9","seq":21900221,"position":1,"parentId":"4198e6806de926ef30000070","content":"* Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart\n\n---- 超声检测\n---- Echocardiography. Echocardiography was performed using a commercially available system (Vivid-I; GE Healthcare, Milwaukee, WI) with a 1.9- to 3.8-mHz phased-array transducer. Images were obtained after 20 min of quiet rest and were separated from a previous training session by 24 h. Two-dimensional, pulsed-Doppler, and color tissueDoppler imaging from standard parasternal, apical, and subcostal positions were performed. The two-dimensional frame rate was 50– 100/s, and the tissue-Doppler frame rate was 100/s for all images. All echocardiography was performed by a single trained sonographer. All data were stored digitally, and poststudy offline data analysis (EchoPac, version 6.5; GE Healthcare) was performed by a study cardiologist blinded to the study time point. Definitions of normalcy were adopted from the most recent American Society of Echocardiography guidelines (13). Left ventricular (LV) ejection fraction, end-diastolic volume, and end-systolic volume were calculated using the modified Simpson’s technique.** LV mass **was calculated using the area-length method. Relative wall thickness was defined as [interventricular septal thickness (mm) posterior wall thickness (mm)/LV internal end-diastolic diameter (mm)]. LA volume was calculated using the biplane arealength method in apical four and two-chamber views. Peak longitudinal LV and right ventricular (RV) tissue velocities were measured offline from two-dimensional color-coded tissue Doppler images an reported as the average of three consecutive cardiac cycles. LV strain was measured by speckled-tracking analysis in the apical four-chamber view and is reported as the average of the six LV segments (basal, midventricular, and apical segments of the interventricular septum and the lateral LV wall). RV strain was measured by tissue Doppler analysis from the apical four-chamber view by placing a 6 2 mm region of interest in the mid-RV free wall at a location half way between the apex and the tricuspid annulus at end diastole. The location of this region of interest was manually adjusted in each systolic frame to ensure optimal tracking of the mid-RV free wall throughout RV systole. The reported value is the average of three consecutive cardiac cycles. Resting heart rates were obtained from the final loop of each study. Body surface area was calculated using the Mosteller formula (17) and all measurements are presented both as raw data and adjusted for body surface area when appropriate."},{"_id":"4132d6197eeb97844d0000b6","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954297,"position":1,"parentId":"4198e5fa6de926ef30000071","content":"* Association of Novel Biomarkers of Cardiovascular Stress With Left Ventricular Hypertrophy and Dysfunction: Implications for Screening\n\n---- 超声测量\n----All attendees underwent standardized 2D transthoracic echocardiography with Doppler color flow imaging. A sonographer or a cardiologist (experienced in echocardiography), blinded to clinical information and biomarker results, read all echocardiograms. The reproducibility of echocardiographic measurements was excellent.14 Interobserver variability ranged from 0.9% to 5% for LVDD, from 2% to 2.9% for diastolic posterior wall thickness, from 3.6% to 6.5% for the interventricular septum in diastole, and from 0.8% to 4% for calculated LV mass. Corresponding figures for intraobserver variability ranged from 0.3% (LVDD) to 4% (interventricular septal thickness).14 Digital M-mode measurements from ¡Ý3 cardiac cycles were averaged to estimate LV internal dimensions in end-systole and enddiastole, and thicknesses of the interventricular septum and LV posterior wall at end-diastole (in accordance with the American Society of Echocardiography [ASE] guidelines).15 Fractional shortening (FS) was calculated using LV internal dimensions at end-diastole and end-systole. In all participants, visual assessment of LV global systolic function was performed in multiple views to estimate the LV ejection fraction (LVEF), which was categorized as normal (LVEF >0.55), borderline (LVEF 0.51 to 0.55), mildly reduced (LVEF 0.41 to 0.50), moderately diminished (LVEF 0.31 to 0.40), or severely impaired (LVEF ¡Ü0.30). The accuracy of the aforementioned estimation of LVEF has been validated in prior reports.16 Both the qualitative variable LVEF and the quantitative variable FS were used to define LV systolic dysfunction12 (ie, the presence of either abnormal LVEF or abnormal FS) because they provide complementary information: the former may not be sensitive for detecting subtle alterations in LV systolic function whereas the latter focuses on the base of the heart (and may miss diminished LV contractility in other regions)"},{"_id":"4125a44471622f36800000c6","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954296,"position":1,"parentId":"4132d6197eeb97844d0000b6","content":"* High-Intensity Interval Training Improves Left Ventricular Contractile Function\n\n---- 超声测定\n---- Echocardiography. The echocardiography tests were performed 2 d before the pretraining GXT and 2 d after posttraining GXT. All subjects arrived at the testing center at 9:00 AM to eliminate any possible circadian effect and were asked to avoid any medicine, alcohol, and caffeine consumption throughout the experiment duration. The subjects were positioned in a 30\u0003 semiupright position oriented in the left semisupine and 60\u0003 lateral decubitus position on an echocardiography imaging table (Cardiac Stress Table w/Angio) (20). The parameters of LV mechanics were measured with the Siemens ACUSON SC2000? ultrasound system (Siemens Medical Solutions USA Inc., Mountain View, CA) using the 4V1c probe (4.5 MHz). This study used one dedicated investigator to perform the collection of echocardiographic data. The data collector was isolated from the data analytic specialist. Moreover, both data collector and analytic specialist were blinded to know the group assignment (HIIT, MICT, or CTL) or experimental time point (preintervention or postintervention) in each subject throughout the period of study. Cardiac images were acquired by 2D and Doppler echocardiography from the parasternal and apical windows (20). The subjects maintained regular breathing patterns, and images were not captured during a breath-hold at end-expiration. M-mode images were used to determine the LV wall and cavity dimensions at end-systole and end-diastole from a parasternal long axis view. Measurements of LV mass and the short fraction index were automatically derived using standard equations. LV ejection fraction (LVEF) was determined using the modified Simpson’s method from the apical four-chamber views. Analysis of Doppler pulsed wave was performed to determine diastolic transmitral blood flow velocities for peak early (E) and late (A) fillings, the ratio of E wave to A wave (E/A), and early diastolic propagation velocity (Vp). The E/A ratio and Vp are sensitive indicators of LV diastolic function (21,22). Higher E/A ratio or Vp reflects that rapid ventricular relaxation promotes a faster influx of blood into the ventricle (21,22). All data were recorded and averaged three times"},{"_id":"41168eb8c90d6987c60000db","treeId":"5fd161d2a87c2c03d5d940a9","seq":21959389,"position":1,"parentId":"4125a44471622f36800000c6","content":"* Exercise-Induced Left Ventricular Remodeling Among Competitive Athletes: A Phasic Phenomenon\n\n---超声测试\n----Cardiac structural measurements were made in accord with current guidelines.17 The LV ejection fraction was calculated using the modified Simpson’s biplane technique. The LV length was measured in the apical 4-chamber view and was defined as the end-diastolic length from the mitral valve hinge point plane to the most distal endocardium at the LV apex. Resting heart rates were obtained from the final loop of each study. Stroke volume was calculated as LV end-diastolic volume?LV end-systolic volume. Cardiac output was calculated as the product of stroke volume and heart rate. To facilitate application of clinical normality cut points,17 LV mass and LV end-diastolic volume were indexed using body surface area as calculated at each study time point. Longitudinal tissue velocities were measured offline from 2D color-coded tissue Doppler images and are reported as the average of 3 consecutive cardiac cycles. Diastolic tissue velocities are an average of medial and lateral values.\n\n17.Lang RM, Badano LP, Mor-Avi V, Afilalo J, Armstrong A, Ernande L, Flachskampf FA, Foster E, Goldstein SA, Kuznetsova T, Lancellotti P, Muraru D, Picard MH, Rietzschel ER, Rudski L, Spencer KT, Tsang W, Voigt JU. Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2015;28:1–39.e14. doi: 10.1016/ j.echo.2014.10.003\n"},{"_id":"410ad2d1251346d6e90000df","treeId":"5fd161d2a87c2c03d5d940a9","seq":21961621,"position":1,"parentId":"41168eb8c90d6987c60000db","content":"Experimental procedure. Subjects rested in a supine position for 10 min before echocardiographic examinations commenced. Examinations were conducted using a Hewlett Packard Sonos 100 ultrasound imaging system with an integrated single-lead ECG. Subjects were examined in the supine position using a 2.5-MHz transducer acoustically coupled with ultrasound transmission gel. Examinations were recorded on Fuji SD E180 high-quality VHS videotape using a Panasonic AG 6200 VHS video recorder. Two-dimensional images (2-D) were obtained from the left parasternal window and used to obtain motion-mode (M-mode) images of the left ventricle. The guidelines of the American Society of Echocardiography (22) were followed for M-mode measurements. Measurements were taken of left ventricular internal dimension at end-diastole (LVIDd, cm) and systole (LVIDs, cm), and of an interventricular septal thickness (ST, cm), posterior wall thickness (PWT, cm), and aortic dimension (cm) at end-diastole. End-diastole was identified as the peak of the R wave on the concurrent ECG, and end-systole as the narrowest point between the interventricular septum and the posterior wall. Left ventricular mass (LVM, g) was calculated from LVIDd, ST, and PWT using the previously validated regression-corrected cube formula of Devereaux and Reichek (5). Ejection fraction percentage was used as an index of contractility and calculated using validated formulae (15). Stroke volume (mL) was calculated as: LVIDd3 LVIDs3. Pulsed wave Doppler measurements were obtained after accurate placement of the sample gate using 2-D imaging from the apical window. Early (E) diastolic inflow, late ventricular inflow (A) after atrial contraction, and systolic outflow envelopes were analyzed for peak flow velocities (vel, cm·s1) and flow integrals (int, cm). Ratios of E to A peak velocities (E:A vel) and integrals (E:A int) were also calculated."},{"_id":"415bb228e78041b5f6000095","treeId":"5fd161d2a87c2c03d5d940a9","seq":21927646,"position":2,"parentId":"4198e6806de926ef30000070","content":"* Sex-related differences in left ventricular structure in early adolescent non-professional athletes\n\n--- LVmass计算"},{"_id":"414c266a38e64a8eda0000a5","treeId":"5fd161d2a87c2c03d5d940a9","seq":21936217,"position":1,"parentId":"415bb228e78041b5f6000095","content":"* High sensitivity cardiac troponins: Can they help in diagnosing myocardial ischaemia?\n\n--- LVH 判断标准\n--- All patients underwent a complete M-mode and two-dimensional echo Doppler study, carried out by commercial equipments with second-harmonic imaging (iE33 X-matrixUltrasound System, Philips, Andover, Massachusetts, USA). Left ventricular mass was calculated in each patient by means of M-mode echocardiography, using the equation of Devereux.7 A value >125 g/m2 (males) and 110 g/m2 (females) was considered as indicative of left ventricular hypertrophy (LVH).\n----Devereux RB. Detection of left ventricular hypertrophy by M-mode echocardiography. Anatomic validation, standardization, and comparison to other methods. Hypertension 1987; 9: II9–II26."},{"_id":"414b05bf7715c922ab0000a9","treeId":"5fd161d2a87c2c03d5d940a9","seq":21936879,"position":2,"parentId":"415bb228e78041b5f6000095","content":"*Association of Troponin T Detected With a Highly Sensitive Assay and Cardiac Structure and Mortality Risk in the General Population\n\n--- LVH 标准\n--- Cardiac and aortic MRI\nwas performed using a 1.5-Tesla system (Intera; Philips Medical Systems, Best, the Netherlands). Left ventricular mass, wall thickness, end diastolic volume (LVEDV), and ejection fraction (LVEF) were calculated from short-axis sequences. Left ventricular hypertrophy (LVH) was defined as left ventricular mass greater than 89 g/m2 g/m2 in women and greater than 112 in men, based on a phenotypically normal subpopulation of the DHS cohort.20 Details of aortic MRI and compliance methods are presented in the eSupplement."},{"_id":"412f79d33be8fa3e840000b9","treeId":"5fd161d2a87c2c03d5d940a9","seq":21950083,"position":3,"parentId":"415bb228e78041b5f6000095","content":"* Association of novel biomarkers of cardiovascular stress with left ventricular hypertrophy and dysfunction: implications for screening\n\n--- LVH标准\n--- Additionally, we performed analyses using the ASE cut points (LVM/height ≥127 g/m in men and ≥100 g/m in women)15 to define LVH. "},{"_id":"41d01b0b6b30a8b7c200011b","treeId":"5fd161d2a87c2c03d5d940a9","seq":21877551,"position":3,"parentId":"41d21070303d1b8b39000210","content":"# Results"},{"_id":"41d01a6b6b30a8b7c200011c","treeId":"5fd161d2a87c2c03d5d940a9","seq":21964542,"position":4,"parentId":"41d21070303d1b8b39000210","content":"# Discussion\nBriefly discuss training response – then cTn, then LV mass (explain why and how) then correlate … \n\n- 传统CVR降低\n-\n- 但cTnT升高,类似研究比较,考虑到坚实的证据,可能有因素影响了适应效应;\n-\n- 所有类似研究都没有考虑LVmass影响,但是我的结果组的训练前后变化不支持\n-\n- 相关分析也支持LVmass无关\n-\n- 急性运动的影响;机制\n-\n- 临床意义\n-\n- 研究限制与进一步工作\n-\n- 结论"},{"_id":"413e87680190423da20000af","treeId":"5fd161d2a87c2c03d5d940a9","seq":21942073,"position":0.5,"parentId":"41d01a6b6b30a8b7c200011c","content":"## 主要结果"},{"_id":"413e86c80190423da20000b0","treeId":"5fd161d2a87c2c03d5d940a9","seq":21942112,"position":1,"parentId":"413e87680190423da20000af","content":"*Evidence of direct cardiac damage following highintensity exercise in chronic energy restriction\n\n--- 意味着什么?\n--- the main findings suggest that individuals who habitually restrict their calorie intake below their bodies’ daily energy requirements, may have elevated biomarkers of exercise-induced myocardial stress from performing high-intensity exercise."},{"_id":"41ca0d0f305e62fb6e000041","treeId":"5fd161d2a87c2c03d5d940a9","seq":21966745,"position":1,"parentId":"41d01a6b6b30a8b7c200011c","content":"## Training response\nHIAT/CAT: VO2max+, body composition (fat-); CON VO2max-\n"},{"_id":"41111056b08e3c8e9b0000de","treeId":"5fd161d2a87c2c03d5d940a9","seq":21966746,"position":0.5,"parentId":"41ca0d0f305e62fb6e000041","content":"* Exercise training and artery function in humans: nonresponse and its relationship to cardiovascular risk factors\n\n---- 心肺适能改善,脂肪降低、“传统危险因素” 不相关\n----**`In agreement with previous meta-analyses (7, 8, 18, 35), our pooled analysis revealed relatively modest improvements in `traditional cardiovascular risk factors`, such as body weight (-0.6 kg), mean arterial pressure (-3 mmHg), and total cholesterol (-0.2 mmol/l).` **\n\n\nFurthermore, these changes in traditional risk factors did not relate to changes in endothelial function after training. Our observations reinforce the presence of a “risk factor gap” (12, 17): the concept that the relatively modest changes in traditional risk factors induced by exercise training (32) cannot fully account for the large clinical benefit of a physically active lifestyle (21, 25). Assessment of endothelial function has powerful predictive capacity for future cardiovascular disease, independent of other risk factors (26). The improvement in endothelial function after training is largely independent of change in risk factors. Clinically, this highlights that the cardioprotective benefits of training should not simply be viewed as those associated with easily measured, traditional cardiovascular risk factors.\n-\n与以前类似的研究一致,两种训练显著改善了传统危险因素,包括:VO2max、Fat、BMI."},{"_id":"414b2dd838e64a8eda0000a7","treeId":"5fd161d2a87c2c03d5d940a9","seq":21966436,"position":1,"parentId":"41ca0d0f305e62fb6e000041","content":"## VO2max、Fat、BMI\n-\n**marked improvements in cardiovascular disease risk factors () in HIAT and CAT were equivalent and consistent with previous studies (Zhang,2020) using...** "},{"_id":"414b2d3c38e64a8eda0000a8","treeId":"5fd161d2a87c2c03d5d940a9","seq":21966437,"position":1,"parentId":"414b2dd838e64a8eda0000a7","content":"*Aerobic High-Intensity Intervals Improve V˙O2max More Than Moderate Training\n\n--- HIT MCT 最大摄氧量影响\n--- V˙ O2max. V˙ O2max is one of the primary determinants of aerobic endurance performance (1). The high–aerobic intensity interval training regimens of 15/15 and the 4 x 4 min performed at the same intensity both revealed significantly higher absolute V˙ O2max responses of 5.5 and 7.3%, respectively, over the moderate- and lower-intensity training of the O2 cost-matched LT and LSD training groups. The effect of interval training **is in line with previous studies** (7,13). It has been suggested a longer duration for training sessions could **compensate for** lower-intensity exercise (16,18). However, the present study, which matched four training protocols for total work and frequency, does not support this claim. Instead, our results **are consistent with those** of Wenger and Bell (29) and Thomas et al. (27), who found that intensity of training **cannot be compensated for by longer duration**. Improvements in V˙ O2max seem to be dependent on fitness level. In a recent paper, we have shown an improvement in V˙ O2max of 7% for cardiovascular patients pathology. "},{"_id":"411e6784d59ce07ace0000d2","treeId":"5fd161d2a87c2c03d5d940a9","seq":21966438,"position":2,"parentId":"414b2dd838e64a8eda0000a7","content":"* Effects of a low-volume aerobic-type interval exercise on VO2max and cardiac mass\n\n---- 摄氧量及体脂降低在HIT和MCT是相似的。\n----Conversely, we observed no significant group difference in V¨B O2max improvement between SIT and CAT (P = 0.25), nor between SIT and HIAT (P = 0.35), whereas the V¨B O2max of the SIT significantly increased (16.7% T 11.6%; Fig. 3) and its ES was large (1.10) (Table 3). **`Improvements in SIT and CAT V¨B O2max were equivalent and consistent with previous SIT studies (1,22) using the modified Wingate protocol.`** The exercise volume of the SIT might have been `too small`, or the sample size of the studies might **not have been sufficient to **detect the difference between SIT and other protocols.”"},{"_id":"41173a37c90d6987c60000d5","treeId":"5fd161d2a87c2c03d5d940a9","seq":21966439,"position":2,"parentId":"41ca0d0f305e62fb6e000041","content":"* Low-volume, high-intensity, aerobic interval exercise for sedentary adults: VO₂max, cardiac mass, and heart rate recovery\n\n---- 描述结果\n----Matsuo et al. (2014) showed that an exercise program comprising an 8-week, 5-day a week, high-intensity aerobic interval training (HAIt) markedly improved maximal oxygen consumption (˙VO2max) in sedentary male subjects. the study also found that the ˙VO2max improvement in HAIt was greater than that in moderate-intensity continuous aerobic training (cAt) and that the left ventricular (lV) mass significantly increased in HAIt, but not in cAt, even though the exercise volume and duration of HAIt were substantially lower than of cAt. "},{"_id":"41ca07f9305e62fb6e000042","treeId":"5fd161d2a87c2c03d5d940a9","seq":21980242,"position":2,"parentId":"41d01a6b6b30a8b7c200011c","content":"## cTnT response\nresting cTnT+\n\n1.横断观察研究几乎一致的发现,新颖的CV危险性标志物, cTn与体力活动水平呈负相关,然而较少纵向干预研究似乎并**不支持体力活动导致安静cTnT降低这一因果关系**。其中XX研究发现耐力训练升高、而力量训练并不改变安静cTnT。只有一项纵向研究发现阳性的结果:增加cTnT但增加值少于对照组。\n...\n2.我们的结果训练导致了安静cTnT增加,这支持141#耐力训练的干预研究但扩展至HIAT及肥胖女性,进而我们的研究显示安静值的增加在HIAT和CAT并没有训差异,这进一步补充了141#,提示当控制了运动功率输出时训练产生的cTnT增加并没有训练方式的差异(独立于训练方式)。另外,cTn与传统危险因子也没有相关性。\n...\n3.当现在的结果以及其他多数干预的纵向研究并不支持运动训练可导致cTnT降低时,我们似乎应慎重否认cTn作为一个训练标志物,这是因为已经有坚实的证据显示cTnT预测了心血管事件。因此我们推测很可能有混淆因素干扰了cTnT水平,以至于不能准确反映其训练效应。\n...\n...\n以下事实:CON恶化的VO2max,可能是由于实验跨过了假期,静态生活加重导致,并没有有影响cTn.\n"},{"_id":"40fe5a740e891323a00000f5","treeId":"5fd161d2a87c2c03d5d940a9","seq":21966822,"position":0.015625,"parentId":"41ca07f9305e62fb6e000042","content":"* Impact of moderate physical activity on the longitudinal trajectory of a cardiac specific biomarker of injury: Results from a randomized pilot study of exercise intervention\n\n----与观察研究比较,纵向研究的优势\n----It is of particular interest to compare these findings with those we observed in the Cardiovascular Health Study (CHS), the **observational cohort** that generated the hypothesis being tested in this study. In that study, a much greater range of physical activity was observed among adults on average 5years younger than in the present study, and with longitudinal change in hs-cTnT assessed for 2 to 3years rather than 12months.4 That the differences in hs-cTnT seen in this pilot randomized trial are smaller than what we observed in the CHS could be the result of the 2- to 3-fold shorter duration of the LIFE-P trial than the observation period in the CHS and much smaller differences in physical activity kcal/wk compared with the most sedentary and most active subjects in the CHS. Furthermore, **`the randomized nature of the present study addresses a principal limitation`** of the CHS analysis or any observational study that does not make it possible to determine whether physical activity is a direct cause for lower cTnT level rises over time or whether lower cTnT rises is simply a marker of better heart health in people who are therefore able to exercise more."},{"_id":"40fdc013c0d8aa1fb30000f9","treeId":"5fd161d2a87c2c03d5d940a9","seq":21966861,"position":1,"parentId":"40fe5a740e891323a00000f5","content":"* The effect of a six-month resistance-type exercise training program on the course of high sensitive cardiac troponin T levels in (pre)frail elderly\n\n----cTn角色转变;纵向研究、生活方式、缺乏干预研究\n----Cardiac troponin is the preferred biomarker for diagnosing non-ST segment elevation myocardial infarction [1]. With the introduction of high-sensitivity assays, cardiac troponin levels became also detectable in apparently healthy subjects. This has **expanded its role** from acute cardiac care to risk stratification and prognostic medicine [2]. Meanwhile, high sensitive cardiac troponin (hs-cTn) has acquired the status of a prognostic biomarker that predicts cardiovascular risk, in addition to established Framingham risk factors (传统危险因素) such as age, sex, blood pressure, and dyslipidemia [3]. **Despite the remarkable consistency in the literature on the association between cardiac troponin levels and increased risk for cardiovascular morbidity and mortality, it is unclear whether preventative measures such as lifestyle intervention programs can influence the course of basal troponin levels.** Suggestive evidence in favor of this hypothesis was provided by **an observational study** by deFilippi et al., showing that higher physical activity levels in elderly subjects were associated with both lower basal cardiac troponin T (cTnT) levels, and a lower probability of a significant increase in cTnT concentrations between consecutive visits [4]. However, no intervention study has evaluated the effect of an exercise program on the concentration of cardiac troponin."},{"_id":"4103cef263376d0ba30000ea","treeId":"5fd161d2a87c2c03d5d940a9","seq":21963037,"position":0.03125,"parentId":"41ca07f9305e62fb6e000042","content":"* The effects of exercise on cardiovascular biomarkers in patients with chronic heart failure\n\n\n----谨慎解释数据\n----A recently published meta-analysis of 10 studies that included 565 patients found exercise to decrease natriuretic peptide levels; however, **understanding the results needs cautious interpretation of the data** as well as confirmation within a randomized trial, which the current study provides using almost twice as many participants (n = 928).1"},{"_id":"40fe4db40e891323a00000f6","treeId":"5fd161d2a87c2c03d5d940a9","seq":21966866,"position":1,"parentId":"4103cef263376d0ba30000ea","content":"* Impact of moderate physical activity on the longitudinal trajectory of a cardiac specific biomarker of injury: Results from a randomized pilot study of exercise intervention\n\n----谨慎解释结果\n----These findings should be considered `cautiously` with appreciation that the study was not designed to test the effect of physical activity on troponin levels.In fact, in sensitivity analysis, we did not find a correlation with positive outcomes of physical activity such as improvements in gait speed and body mass index and change in cTnT level. Moreover, the number of subjects with N50% increase in their hs-cTnT in the LIFE-P study was small and the difference between the 2 groups was not statistically significant. However, this finding is not without precedent, as the inflammatory marker interleukin-6, which is also associated with cardiovascular outcomes, correspondingly increased less in those LIFE-P participants assigned to physical activity vs successful aging.14 Potentially, the palliative effect of physical activity on cardiac injury may be mediated through an anti-inflammatory mechanism. A clinical correlate to support these biomarker findings is the marked reduction in cardiovascular risk that has been previously reported from observational cohorts of adults who increase their physical activity levels.7-10"},{"_id":"415ab966ff62e93dca000099","treeId":"5fd161d2a87c2c03d5d940a9","seq":21927769,"position":0.0625,"parentId":"41ca07f9305e62fb6e000042","content":"* Sex-based differences in serum cardiac troponin I, a specific marker for myocardial injury, after cardiac surgery\n\n--- 先排除。。。影响\n--- It is important to emphasize that cardioplegic protocols were identical in both men and women enrolled in this study. Therefore, differences found in the present study **cannot be attributed to** intraoperative myocardial preservation techniques."},{"_id":"4138cb1fa80a3e0c870000b4","treeId":"5fd161d2a87c2c03d5d940a9","seq":21966511,"position":2,"parentId":"415ab966ff62e93dca000099","content":"* High-sensitivity cardiac troponin T in young, healthy adults undergoing non-cardiac surgery\n\n--- 排除。。\n--- cTn assays have a nearly 100% cardiac tissue specificity, except for some patients with chronic muscular disease who have increased concentrations of circulating hscTnT because of re-expression of presumably fetal proteins.19e21 It is unlikely, therefore, that skeletal muscle injury during orthopaedic surgery caused postoperative cTn increases in our patient population."},{"_id":"4196d40d6de926ef3000007a","treeId":"5fd161d2a87c2c03d5d940a9","seq":21966914,"position":0.125,"parentId":"41ca07f9305e62fb6e000042","content":"* Endurance exercise training volume is not associated with progression of coronary artery calcification\n\n---- 阳性率 与其他研究比较\n---- In the present cohort, **the prevalence of CAC at baseline was 34%**, with a median CAC of 0 (0-6) Agatston units. For subjects with CAC at baseline, the median CAC was 12 (3-37) Agatston units. Thus, the baseline CAC score in the present cohort was comparable with the CAC scores in similar age groups from other population-based cohorts,23,24 but lower than previously reported in highly active subjects.3-6,25 During the 4.1 ± 0.3 years of follow-up, only 15 subjects (25%) had progression of CAC = 10 Agatston units. The mean ? CAC was 15 ± 40 Agatston units. This rate of progression of CAC was modest compared with other studies of the progression of CAC on CCTA.13,21,22,26-28 In the Heinz Nixdorf Recall Study (HNRS), subjects 45-50 years of age had a mean ? CAC progression of 38 Agatston units over a 5-year period.21 In HNRS, authors reported that once the CAC process had begun, the progression of CAC followed an exponential trajectory.2"},{"_id":"4166b4d222fb2a324900008a","treeId":"5fd161d2a87c2c03d5d940a9","seq":21963061,"position":1,"parentId":"4196d40d6de926ef3000007a","content":"* Cardiac Troponin T in Healthy Full‑Term Infants\n\n---- 以前的研究,仍存在的空白\n---- Several studies have investigated cTnT values in infants after admission for neonatal care [3¨C5, 10¨C24]. Only a limited number of studies have determined cTnT values primarily in healthy full-term infants [1, 2, 25¨C28]. All but one of these studies have been performed before the introduction of hs-cTnT assays [2] and a considerable proportion of cTnT values were even below the detection limit [1, 25]. Cardiac troponin T has in most cases been determined either in cord blood [1, 2, 25, 26, 28] or in peripheral blood [3, 11¨C13, 17¨C19, 21, 29]. Only a few studies have done sequential measurements of cTnT, and primarily in asphyxiated or premature infants [5, 10, 16]. We aimed to investigate hs-cTnT values in cord blood and during the first week of age, in healthy full-term infants born either after spontaneous onset of delivery, or after planned caesarean section (CS). We hypothesized that hs-cTnT would be elevated already in cord blood, compared with the adult upper reference limit, and that it would further increase over the first 2¨C5 days of age. We finally hypothesized that hs-cTnT values would be higher in infants born after vaginal delivery compared with infants born after planned CS","deleted":false},{"_id":"41612974ffcb296715000090","treeId":"5fd161d2a87c2c03d5d940a9","seq":21926538,"position":1,"parentId":"4166b4d222fb2a324900008a","content":"* Metabolic syndrome is associated to high-sensitivity cardiac troponin T elevation\n\n--- 研究有限;不一致;本研究的优势:\n---Data regarding the association between highly sensitive troponin and MetS are limited. In both children and adults, there is disagreement on whether obesity per se or metabolic abnormalities are the cause of increased hs-TnT (Pervanidou et al. 2013, Zeng et al. 2016). In adults, reports from a relatively small sample in Japan found no significant association between MetS and hs-TnT (Hitsumoto and Shirai 2015). However, recent evidence from a sub-analysis of the ARIC (Atherosclerosis Risk in Communities) study showed a significant association between MetS and hs-TnT (Pokharel et al. 2017). Our results in a relatively large cohort are in line with those of the ARIC sub-analysis. In addition, the observed association between male gender and hs-TnT concur with the ARIC sub-analysis and a large recent meta-analysis including 154,052 participants assessing predictors for hs-Tn elevation (Pokharel et al. 2017, Willeit et al. 2017)."},{"_id":"4139cc3fa80a3e0c870000b2","treeId":"5fd161d2a87c2c03d5d940a9","seq":21966934,"position":1,"parentId":"41612974ffcb296715000090","content":"*Cardiac Biomarker Release after Endurance Exercise in Male and Female Adults and Adolescents\n\n--- 对cTnT的讨论\n--- This study confirms that the exercise-induced release of cTn and NT-proBNP is not exclusive to an ultra-endurance effort in adult athletes.5,6,23,24 \n--- There is some evidence to suggest that cTn release during prolonged exercise is positively associated with exercise intensity.25,26 Thus, the high intensity shown by our swimmers could explain the release of hs-cTnT. \n--- The percentage of participants exceeding the URL (62%) of hscTnT was comparable with the only previous study with male adult swimmers who performed the same exercise test (64%).23 \n--- These results confirmed findings of marked individual variability in the release of hs-cTnT with exercise.6,10 This variability could partly be explained by differences in the %HRmax between the subjects and could be linked to recent findings that suggest that the release of hs-cTnT with exercise is higher in subjects with more training or with better “athletic” status5,6 who are usually capable of maintaining higher %HRmax values for specific durations of effort. This seems the most probable explanation for the absence in some subjects of hs-cTnT increase after exercise. \n--- The %HRmax does not explain all of the variability in the hs-cTnT and high %HRmax values were observed in subjects with negligible release of hs-cTnT and this suggests that some other, currently unknown, factor/process may make participants more or less likely to release cTn in response to exercise. \n--- There was much more consistency in the overall “pattern” or “kinetics” of hs-cTnT throughout the 24hour recovery period. Our data reflect a rapid rise in hscTnT in the early hours of recovery, with most of the subjects reaching a peak at 3 hours, with close to complete recovery to baseline at 24 hours. These observations were consistent between individuals and largely agreed with the few studies reporting detailed hs-cTnT kinetics over 24 hours.6,10,23\n--- Several studies have suggested that the cTn release after endurance exercise might be greater among adolescent athletes compared with adults, possibly because of the immature cardiac muscle of the adolescent.10,12,13,28,29 The results of this study do not support this hypothesis and agree with a previous work in which no differences in cTnI release were observed in a male sample after a basketball match between adolescents and adults.14\nConversely, in the only other controlled study according to the adolescent-adult condition, the assessment revealed that adolescents runners had a higher mean postexercise value of hs-cTnT, with a greater number of subjects exceeding the peak URL and more time to recovery.10 One possible explanation for these contradictory findings may be associated with differences in the pubertal status of the adolescents between the studies. Adolescents were Tanner stages 3-5 in the current study, 4-5 in basketball players,14 and 2-3 in runners10 suggesting than only early Tanner stage may exert an influence upon hs-cTnT. In runners it was observed that adolescents at Tanner stage 2 had higher peak hs-cTnT than those ofTanner stage 3, although the difference was not statistically significant.10 Ongoing work should determine the causes of and suggest that the high between-subject variability. Instead, our results agree with the study evaluating the runners10 adolescent-adult and pubertal status do not influence NTproBNP release with exercise. This is consistent with our observation that no difference between groups in baseline NTproBNP exists; this strongly explains postexercise NT-proBNP values."},{"_id":"41544df565ab5d79ac0000a4","treeId":"5fd161d2a87c2c03d5d940a9","seq":21963062,"position":2,"parentId":"4196d40d6de926ef3000007a","content":"* Cardiac troponin I is released following high-intensity short-duration exercise in healthy humans\n\n---- **比较阳性率,不同人群**\n---- The use of hs-cTnT for screening of the general population\nhas been evaluated. In the Dallas Heart Study, a multiethnic population-based study, over a median of 6.4 years of followup, the prevalence of measurable cTnT above the limit of blank with the highly sensitive assay (≥3 ng/L) was 25% (versus 0.7% with standard assays).10 Of note, in the current study, the prevalence of hs-cTnT >3 ng/L was notably higher (78.5%), presumably due to the older age and larger proportion of males in the CCLS compared with the Dallas Heart Study. In the Dallas Heart Study, all-cause mortality and left ventricular hypertrophy increased significantly from the lowest hs-cTnT category (<3 ng/L) to the highest (≥14 ng/ L).10 In an older population enrolled in the Cardiovascular Health Study, the prevalence of hs-cTnT ≥3 ng/L was 66.2% and both the baseline hs-cTnT level and changes in troponin levels were found to provide prognostic information.11 In the Cardiovascular Health Study, we previously reported an association between regular exercise and smaller increases in hs-cTnT over time.18 However, the association with objectively measured CRF has not been reported previously.","deleted":false},{"_id":"412b767f6721a5afde0000bf","treeId":"5fd161d2a87c2c03d5d940a9","seq":21963063,"position":3,"parentId":"4196d40d6de926ef3000007a","content":"* Association of Troponin T Detected With a Highly Sensitive Assay and Cardiac Structure and Mortality Risk in the General Population\n\n---- cTnT阳性率\n----Using a highly sensitivity assay, cTnT was detectable in approximately 25% of adults in the general population and was associated with structural heart disease and risk of subsequent all-cause mortality.","deleted":false},{"_id":"412673fc71622f36800000c1","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954176,"position":1,"parentId":"412b767f6721a5afde0000bf","content":"* High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population\n\n--- cTnT阳性率。\n--- Detectability rates differ among assays. In the Generation Scotland Scottish Family Health Study on 19501 individuals, hs-cTnI and hscTnT were detectable in 74.8% and 53.3% of participants, respectively.33 Similarly, in a meta-analysis of 28 trials involving a total of 154 052 individuals, the pooled detectability rates were 82.6% for hscTnI and 69.7% for hs-cTnT.34"},{"_id":"415533fe65ab5d79ac0000a1","treeId":"5fd161d2a87c2c03d5d940a9","seq":21963059,"position":4,"parentId":"4196d40d6de926ef3000007a","content":"* Impact of an endurance training program on exercise-induced cardiac biomarker release\n\n---- 讨论 **安静值高 **讨论相关\n---- We observed higher baseline and peak postexercise values for hs-cTnT after 14 wk of running training, which also differentiated this group from the control cohort. This supports some previous cross-sectional data from athletes of different training status (Legaz-Arrese et al., unpublished observations; and Ref. 24) but does contradict past field-based studies of runners with higher and lower selfreported training volumes (e.g., Ref. 20). The assay precision and method used to quantify the level of training may also be confounding factors in the relationship observed in previous studies. In the largest case series data in marathoners, Fortescue et al. (5) noted that the runners with less prior experience in marathon running were more likely to have cTnT increases. They also found no relationship between race time and the increase in cTnT, suggesting that the number of previous marathons may not be the most appropriate way to quantify the current level of training. Furthermore, the authors indicated no significant relationship between the release of cTnT and average training pace or average miles run per week during the last 3 mo. In the same direction, a multiple regression analysis demonstrated that marathon experience was a significant predictor of postmarathon hs-cTnT (19). Once again, the authors did not establish a relationship between marathon time and the release of hs-cTnT and did not gather other data on the level of training of the athletes. The association observed by Nie et al. (21) and Tian et al. (39) between the number of years of training and cTnT or cTnI release after a half-marathon in adolescent subjects was weak and could have been influenced by the maturity status of the adolescents. Moreover, in neither of these studies did the authors observe a relationship for other indicators of the level of training, such as weekly training distance. Finally, using a prospective study design, Mehta et al. (15) revealed that average miles run per week in the last 3 yr (an indicator of previous training experience) was negatively associated with postmarathon cTnI release. No association, however, was observed for the current training status (miles run per week in the last 4 mo) or for race time","deleted":false},{"_id":"4125f95671622f36800000c3","treeId":"5fd161d2a87c2c03d5d940a9","seq":21962949,"position":0.1875,"parentId":"41ca07f9305e62fb6e000042","content":"## 训练效应\n\n与141#一致,但有些研究不一致(没有变化)。\n解释这个不一致,可能与采血点的选择有关?引出:48小时仍然高,以前的观察窗口短,延长时会发现仍升高。"},{"_id":"4125f87b71622f36800000c4","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954249,"position":1,"parentId":"4125f95671622f36800000c3","content":"* Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart\n\n---- 结果:LVmass+,**restingcTnT=**, VO2max+\n"},{"_id":"40fe23af0e891323a00000f8","treeId":"5fd161d2a87c2c03d5d940a9","seq":21964562,"position":1,"parentId":"4125f87b71622f36800000c4","content":"* Impact of moderate physical activity on the longitudinal trajectory of a cardiac specific biomarker of injury: Results from a randomized pilot study of exercise intervention\n\n----非常小的运动量,急性影响cTn的可能性降低\n---Furthermore, the intensity of the physical activity intervention arm was moderate, as suggested by the achieved physical activity of 135minutes per week in this group, lower than the consensus guideline recommendation of 150minutes weekly.16\n"},{"_id":"41a1b9fbe0cc008572000063","treeId":"5fd161d2a87c2c03d5d940a9","seq":21899922,"position":0.25,"parentId":"41ca07f9305e62fb6e000042","content":"* High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014\n\n----本研究,支持 另外一项研究的效度。\n----In the current study, we demonstrate for the first time an association between current snus tobacco use and lower cTn concentrations in the resting state. This lends further support to the validity of the finding of an inverse association between tobacco smoking and cTn observed in the population-based setting.16,17\n----The current results, combined with data from prior reports observing an inverse association between cigarette smoking and concentrations of cTn, suggest that the **`effect is real`** and underscore the need for further experimental research exploring the potential underlying mechanisms for this apparently paradoxical phenomenon."},{"_id":"41b6306add968a8adc000053","treeId":"5fd161d2a87c2c03d5d940a9","seq":21957235,"position":0.5,"parentId":"41ca07f9305e62fb6e000042","content":"### 解释为何cTnT升高:急性运动的影响未恢复?\n* early evaluation of myocardial injury by means of high-sensitivity methods for cardiac troponins after strenuous and prolonged exercise\n--- it is important to also consider the **`higher baseline`** cardiac troponin levels measured in professional endurance athletes.53 These values could be due to the high and prolonged exercise training that they carry out daily. in fact, professional endurance athletes train at least 6 times every week for at least 4-6 hours each session. **it is logical to think that this strenuous and continuous training raises cardiac troponin levels, without the necessary rest time to return to normal biomarker levels**.53, 57 in fact, several studies have shown that after an intense exercise or an endurance race it takes about 24-48 hours to measure normal troponin values in athletes.3, 57, 58 on the other hand, however, **several authors have shown that even after an amateur physical activity there is a significant increase in cardiac troponin, however `without ever exceeding` url.59-61** These studies have opened an interesting scientific debate on the beneficial role of physical activity, on the right amount of physical exercise and in particular on the effects that intense physical effort can have on the heart.2, 10, 53, 58 in fact, several studies have shown that troponin elevation could be a physiological response of the heart to exercise within a certain limit of effort, to become a paraphysiological or even pathological response if the physical effort is strenuous and prolonged.3, 11, 53, 58 already more than 2000 years ago, Hippocrates spoke of the “right dose” of exercise for health. a few years ago, Wilson et al.62 had described that long-term strenuous aerobic exercise could be associated with deleterious adaptive changes in cardiac structure, function and electrical activity."},{"_id":"419caa79e7d3819fe2000066","treeId":"5fd161d2a87c2c03d5d940a9","seq":21899799,"position":1,"parentId":"41b6306add968a8adc000053","content":"* High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014\n\n----概述运动性cTn及意义挑战\n----提示进一步工作\n----**`An increase in concentrations of cTn following intense exercise is commonly observed`**.2 Activity-related changes in serum enzymes have been known for several decades,18,19 and, in line with these observations, exercise-induced troponin increase has traditionally been considered a benign and physiological phenomenon. However, recent observations demonstrating associations between the magnitude of postexercise troponin response and cardiovascular disease and outcome20,21 challenge this concept. Moreover, **`it highlights that more detailed information is needed on determinants`** of the magnitude of transient elevations of cTn following exercise. "},{"_id":"413a5ca4a80a3e0c870000b1","treeId":"5fd161d2a87c2c03d5d940a9","seq":21944322,"position":1,"parentId":"419caa79e7d3819fe2000066","content":"*Traditional and new candidate cardiac biomarkers assessed before, early, and late after half marathon in trained subjects\n\n--- 对训练的适应\n--- Of interest, the suppressed resting concentration of AAT in our athletes, in agree with the unique previous results obtained in professional cyclists, could provide insights on **`how body adapt to regular training`** (Semple et al. 2006). In fact, low concentration of CRP and other proinflammatory proteins has been repeatedly found in many types of athletes (Semple et al. 2006; Mattusch et al. 2000; Tomaszewski et al. 2004). This result, associated with the anti-inflammatory nature of exercise itself, evidences the uselessness of antiinflammatory proteins to be upregulated in trained athletes. The situation can change for other conditions, such as in HF, where α-1 proteins, of which AAT is the major component, increase (Lubrano et al. 2017). In this case, it is plausible that the increase of AAT suppresses the negative effects of elastase production and indirectly inhibits complement activation, that is an anti-inflammatory effect. Since it is the first observation in this setting, this finding must be confirmed in further studies."},{"_id":"41577e40e35d49456d00009e","treeId":"5fd161d2a87c2c03d5d940a9","seq":21929621,"position":2,"parentId":"41b6306add968a8adc000053","content":"* Individual variability in cardiac biomarker release after 30 min of high-intensity rowing in elite and amateur athletes\n\n--- **`更高的安静值,解释机制`**\n--- We do not know the reasons behind the higher baseline cTnI levels in elite versus amateur rowers. A previous study showed that runners with detectable hs-cTnT were significantly better trained than runners in whom hs-cTnT was not detectable (Saravia et al. 2010). Furthermore, we found that a controlled endurance training intervention resulted in higher pre-exercise hscTnT values (Legaz-Arrese et al. 2015). One hypothesis is that this effect is due to successive training sessions and **limited recuperation time** for elite athletes. However, this seems unlikely to be a factor in this study because subjects were required to abstain from vigorous athletic activity for 48 h before the exercise test. Furthermore, if the greater baseline cTnI values were a consequence of incomplete recuperation, the elite rowers ought to have had similarly increased baseline NT-proBNP levels, based on the results of this study. In a previous study, significantly higher baseline hscTnT concentrations were found in males compared with females (Mingels et al. 2009). Given that mean **heart size** is larger for male and elite athletes than for female and amateur athletes (Legaz-Arrese et al. 2006; Legaz Arrese et al. 2005), it is reasonable to expect different reference cTn values between these groups. Future research may wish to address this issue."},{"_id":"41399369a80a3e0c870000b3","treeId":"5fd161d2a87c2c03d5d940a9","seq":21945066,"position":3,"parentId":"41b6306add968a8adc000053","content":"*High-Sensitivity Cardiac Troponin After Cardiac Stress Test: A Systematic Review and Meta-Analysis\n\n--- 以前一直假定,但最近质疑\n--- Until recently—before the introduction of hs-cTn assays—it was widely assumed that cTn is only released during myocardial cell necrosis. Recent hs-cTn data, however, have strongly questioned this assumption. Data obtained from young, healthy athletes have shown that hs-cTn levels may rise... "},{"_id":"416ee0551fdc97a30f000083","treeId":"5fd161d2a87c2c03d5d940a9","seq":21916992,"position":2,"parentId":"41ca07f9305e62fb6e000042","content":"## 机制\n安静释放以及训练升高的机制 "},{"_id":"4159a62c486e3540a800009b","treeId":"5fd161d2a87c2c03d5d940a9","seq":21928676,"position":0.125,"parentId":"416ee0551fdc97a30f000083","content":"* Predictors of cardiac troponin release after a marathon\n\n--- 我们的研究有贡献,但机制仍需进一步研究,解决这个机制有重要意义\n--- Whilst our study provides novel insight into factors that relate to the exercise-induced increase in cTnI, studies are warranted to directly examine the underlying mechanisms of elevated post-race troponin levels. Such information will reveal important information regarding the physiological versus pathological nature of troponin release in athletes after exercise."},{"_id":"4166baea22fb2a3249000086","treeId":"5fd161d2a87c2c03d5d940a9","seq":21922526,"position":0.25,"parentId":"416ee0551fdc97a30f000083","content":"* Cardiac Troponin T in Healthy Full‑Term Infants\n\n---- 原因不十分清楚,几种可能的解释\n---- What causes the transient rise of cTnT in newborn infants is not fully understood. **One possible explanation could be** the transient hypoxia related to delivery, in combination with the physiological circulatory adaptation starting after birth. The circulatory adaptation continues during the first days of life which might explain the elevated values of cTnT seen several days after delivery. **It is not clarified at what time point cTnT reaches its highest levels postnatally nor **when it equals adult reference values."},{"_id":"413e89f10190423da20000ae","treeId":"5fd161d2a87c2c03d5d940a9","seq":21942066,"position":1,"parentId":"4166baea22fb2a3249000086","content":"*Evidence of direct cardiac damage following highintensity exercise in chronic energy restriction\n\n---机制不清\n----The main findings of this case report are that low-energy availability may be associated with augmented cTnI release following anaerobic exercise. Whether the appearance of clinically raised levels of cTnI in this work is because of pathological mechanisms, or, a temporary and benign physiological response like that in endurance exercise, or an isolated individual response is not certain. "},{"_id":"4122451bcbc76f03b10000cf","treeId":"5fd161d2a87c2c03d5d940a9","seq":21955799,"position":2,"parentId":"4166baea22fb2a3249000086","content":"* Association of Troponin T Detected With a Highly Sensitive Assay and Cardiac Structure and Mortality Risk in the General Population\n\n---- 解释cTnT增加\n----One hypothesis is that an upward trajectory of levels of hs-cTnT **may represent a process of increased myocyte apoptosis with subsequent replacement with fibrosis and increased cardiac stiffness. **Recent evidence from magnetic resonance imaging shows a relatively high (17%; 95% CI: 14% to 19%) prevalence of unrecognized myocardial infarctions in a cohort of older adults (28). Therefore, occult myocardial infarction could be 1 potential mechanism to account for increased hscTnT levels. Another hypothesis is that an upward trajectory of NT-proBNP levels may represent subtle increases in fluid and sodium retention from both cardiac and noncardiac mechanisms increasing a vulnerability to symptomatic HF. Inclusion of both an increasing hs-cTnT level and NTproBNP level may identify those most likely to have a cardiac-specific mechanism for increasing fluid retention and potentially identify those still asymptomatic individuals to be targeted with a specific therapy, such as aldosterone antagonists, that might reduce cardiac fibrosis and fluid retention."},{"_id":"4103abfa63376d0ba30000ec","treeId":"5fd161d2a87c2c03d5d940a9","seq":21963075,"position":1,"parentId":"4122451bcbc76f03b10000cf","content":"*Cardiac Biomarker Release after Endurance Exercise in Male and Female Adults and Adolescents\n\n--- 对cTnT的讨论\n--- This study confirms that the exercise-induced release of cTn and NT-proBNP is not exclusive to an ultra-endurance effort in adult athletes.5,6,23,24 There is some evidence to suggest that cTn release during prolonged exercise is positively associated with exercise intensity.25,26 Thus, the high intensity shown by our swimmers could explain the release of hs-cTnT. The percentage of participants exceeding the URL (62%) of hscTnT was comparable with the only previous study with male adult swimmers who performed the same exercise test (64%).23 These results confirmed findings of marked individual variability in the release of hs-cTnT with exercise.6,10 This variability could partly be explained by differences in the %HRmax between the subjects and could be linked to recent findings that suggest that the release of hs-cTnT with exercise is higher in subjects with more training or with better “athletic” status5,6 who are usually capable ofmaintaining higher %HRmax values for specific durations of effort. This seems the most probable explanation for the absence in some subjects of hs-cTnT increase after exercise. The %HRmax does not explain all of the variability in the hs-cTnT and high %HRmax values were observed in subjects with negligible release of hs-cTnT and this suggests that some other, currently unknown, factor/process may make participants more or less likely to release cTn in response to exercise. There was much more consistency in the overall “pattern” or “kinetics” of hs-cTnT throughout the 24hour recovery period. Our data reflect a rapid rise in hscTnT in the early hours of recovery, with most of the subjects reaching a peak at 3 hours, with close to complete recovery to baseline at 24 hours. These observations were consistent between individuals and largely agreed with the few studies reporting detailed hs-cTnT kinetics over 24 hours.6,10,23\n--- Several studies have suggested that the cTn release after endurance exercise might be greater among adolescent athletes compared with adults, possibly because ofthe immature cardiac muscle of the adolescent.10,12,13,28,29 The results of this study do not support this hypothesis and agree with a previous work in which no differences in cTnI release were observed in a male sample after a basketball match between adolescents and adults.14\nConversely, in the only other controlled study according to the adolescent-adult condition, the assessment revealed that adolescents runners had a higher mean postexercise value of hs-cTnT, with a greater number of subjects exceeding the peak URL and more time to recovery.10 One possible explanation for these contradictory findings may be associated with differences in the pubertal status of the adolescents between the studies. Adolescents were Tanner stages 3-5 in the current study, 4-5 in basketball players,14 and 2-3 in runners10 suggesting than only early Tanner stage may exert an influence upon hs-cTnT. In runners it was observed that adolescents at Tanner stage 2 had higher peak hs-cTnT than those ofTanner stage 3, although the difference was not statistically significant.10\nOngoing work should determine the causes of and suggest that \nthe high between-subject variability. Instead, our results agree with the study evaluating the runners10 adolescent-adult and pubertal status do not influence NTproBNP release with exercise. This is consistent with our observation that no difference between groups in baseline NTproBNP exist; this strongly explains postexercise NT-proBNP values."},{"_id":"416ed9471fdc97a30f000084","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954169,"position":0.5,"parentId":"416ee0551fdc97a30f000083","content":"* High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population\n\n--- 机制并未完全理解;解决机制有助于确定预防干预的新靶点。\n--- The predominate trigger and exact mechanisms of cTnT/I release from cardiomyocytes in asymptomatic individuals **are incompletely understood**.58 Elucidation of the underlying pathophysiology by studies addressing sensitive indices of CV function, besides improving our understanding, may further contribute to the identification of **novel targets** for preventive interventions. "},{"_id":"41c968763ff9d430be000047","treeId":"5fd161d2a87c2c03d5d940a9","seq":21916993,"position":1,"parentId":"416ee0551fdc97a30f000083","content":"### 机制:心肌细胞更新\n* Early evaluation of myocardial injury by means of high-sensitivity methods for cardiac troponins after strenuous and prolonged exercise\n\n---- unfortunately, to date, the exact mechanism is unknown.5, 6, 23, 24\n----an interesting question concerns the physiological interpretation of biomarker circulating levels, measured with hs-cTn methods, `in healthy subjects at rest`. Several authors have suggested that the hs-cTn concentration is a reliable index of **`physiological cardiomyocyte renewal`**.5, 7, 8, 23, 24 indeed, the 99th percentile url values of hscTni methods (about 14-47 ng/l) correspond to the same amount of cardiomyocyte renewal evaluated in experimental animals and adult subjects.5, 7, 8, 23, 24\n\n---- 中位数与99th差10-15倍:细胞更新需增加10-15倍才能达到99th阈值也就是心肌损伤阈值results can be explained by considering that the distribution of hs-cTni values in healthy adult subjects is markedly asymmetrical: as a consequence, the 99th percentile url value is up to 10- to 15-fold higher than the median value (Table i). This means that the physiological cardiomyocyte renewal should increase 10-15 folds before the hs-cTn concentration value can exceed the threshold of myocardial injury.7, 8, 16, 35"},{"_id":"41c959d43ff9d430be000048","treeId":"5fd161d2a87c2c03d5d940a9","seq":21882126,"position":1,"parentId":"41c968763ff9d430be000047","content":"-Nosaka K, Clarkson PM. Relationship between post-exercise plasma CK elevation and muscle mass involved in the exercise. Int J Sports Med. 1992\n-\n-\n**Although the mechanism underlying** muscle protein release from damaged muscle cells is not clear, it is generally believed that an abnormality or disturbance of the plasma membrane is necessary (12,22,23). In fact, plasma membrane lesions have been shown in dystrophic muscle fibers, and patients with muscular dystrophy show elevated levels of CK in the blood (6,23). Eccentric exercise is also thought to produce plasma membrane damage (1,9). This damage could induce a loss of intracellular calcium homeostasis and trigger a sequence of events leading to cell necrosis (1,8,25). Either plasma membrane damage or muscle cell necrosis, or a combination of the two would be associated with the large CK increase after eccentric exercise."},{"_id":"419c893ae7d3819fe2000068","treeId":"5fd161d2a87c2c03d5d940a9","seq":21899810,"position":1,"parentId":"41c959d43ff9d430be000048","content":"* High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014\n\n----解释机制\n----Although the performance-enhancing effects of nicotine are unlikely to explain the differences observed, higher myocardial perfusion as a consequence of nicotine use **could be a possible mechanism for** lower circulating concentrations of cTn in snus users.\n----Associations between smoking and improved short-term outcomes have been described for several cardiovascular disorders.30¨C32 The mechanisms underlying the ¡°smokers¡¯ paradox¡± **are unknown, but a possible explanation could be that tobacco protects myocytes by **preconditioning.31,32 Whether this apparently cardioprotective effect of smoking also holds true for snus is unknown. Furthermore, if the smokers¡¯paradox is the result of the biological effects of tobacco or could be explained by selection and/or unmeasured bias is an ongoing discussion.30,33"},{"_id":"41bf7f77482816e167000051","treeId":"5fd161d2a87c2c03d5d940a9","seq":21886636,"position":2,"parentId":"41c968763ff9d430be000047","content":"### physiological cardiomyocyte renewal\n* Measurement of circulating concentrations of cardiac troponin I and T in healthy subjects: a tool for monitoring myocardial tissue renewal?\n\n"},{"_id":"41b2d1c89d055c7daf000057","treeId":"5fd161d2a87c2c03d5d940a9","seq":21892288,"position":3,"parentId":"41c968763ff9d430be000047","content":"### 凋亡\n* How is cardiac troponin released from injured myocardium?\n----Cardiomyocytes might die also because of enhanced apoptosis. The extent to which these alternative mechanisms of cTn release contribute to **small hs-cTn elevations which are seen in daily** clinical practice **still remains to be shown more definitively, but this should be an area of further future investigation**"},{"_id":"41af865d02146938d4000058","treeId":"5fd161d2a87c2c03d5d940a9","seq":21892782,"position":4,"parentId":"41c968763ff9d430be000047","content":"### 心肌细胞更新\n* Measurement of circulating concentrations of cardiac troponin I and T in healthy subjects: a tool for monitoring myocardial tissue renewal?\n-----hypothesis that cardiac troponins can be released from cardiomyocytes, even in healthy adult subjects as a result of a process related to ‘‘`physiological renewal`’’ of the human myocardium and `possibly enhanced by physical exercise` or aging.\n----\n----**年轻人更新率更高**\nThe results of this study suggested that cardiomyocytes can renew themselves, with a gradual decrease in annual turnover from 1% at the age of 25 years to 0.45% at the age of 75 years, with, on the whole, fewer than 50% of cardiomyocytes exchanged during a normal life span (26).\n"},{"_id":"4126850571622f36800000c0","treeId":"5fd161d2a87c2c03d5d940a9","seq":21957190,"position":3,"parentId":"41ca07f9305e62fb6e000042","content":"* Metabolic syndrome is associated to high-sensitivity cardiac troponin T elevation\n\n--- 我们的结果与以前的研究一致,但我们的研究有新贡献\n---Because not all of these patients will go on to develop overt heart failure or other CVD, more accurate and personalized risk assessment is needed. The findings of the ARIC sub-analysis suggest that hs-TnT testing can further refine risk stratification in patients with MetS. Our results corroborate this concept in that it establishes not only an association between Mets and hs-Tn but suggests a continuous relation between the metabolic burden (i.e. the number of MetS components) and hs-TnT in asymptomatic subjects."},{"_id":"4104fe53dd6f92fd2e0000e3","treeId":"5fd161d2a87c2c03d5d940a9","seq":21962950,"position":1,"parentId":"4126850571622f36800000c0","content":"\n* Relation of Lifestyle Factors and Life’s Simple 7 Score to Temporal Reduction in Troponin Levels Measured by a High-Sensitivity Assay (from the Atherosclerosis Risk in Communities Study)\n\n---- 我们的研究扩展这个发现 ,到 HIT\n----Additionally, sedentary behavior was associated with progression of subclinical myocardial damage, whereas moderate physical activity appeared to have a protective effect in older adults. Our study extends these findings to a middle-aged population and demonstrates the benefit of other health behaviors, such as maintaining both a normal weight and a favorable LS7 score."},{"_id":"4104e3e0dd6f92fd2e0000e6","treeId":"5fd161d2a87c2c03d5d940a9","seq":21962954,"position":1,"parentId":"4104fe53dd6f92fd2e0000e3","content":"* The effects of exercise on cardiovascular biomarkers in patients with chronic heart failure\n\n---- 我们的结果 挑战了一个假设:我们并没有发现。。。尽管结构化的系统训练\n----Findings from this study `challenge` the hypothesis that exercise training improves commonly evaluated cardiovascular biomarkers in patients with chronic HF. **We found that plasma levels of NT-proBNP, hs-CRP, or cTnT did not significantly improve at 3 months despite a structured exercise training program**, even after accounting for baseline biomarker levels. Although patients who tended to exercise more had lower levels of NT-proBNP and hsCRP and decreased risk of adverse clinic outcomes, volume of exercise did not influence serial levels. Only decreases in NT-proBNP translated to improvements in functional capacity and reductions in risk of clinical outcomes. "},{"_id":"40ff254c4046666ff20000ef","treeId":"5fd161d2a87c2c03d5d940a9","seq":21964506,"position":4,"parentId":"41ca07f9305e62fb6e000042","content":"* The effect of exercise training on the course of cardiac troponin T and I levels: three independent training studies\n\n----高敏、危险分层、坚实的证据、可干预、受生活方式影响如运动训练\n----The development of increasingly sensitive assays for cardiac troponin has now reached the point where cardiac troponin concentrations can be accurately assessed in the majority of subjects from a healthy reference population1. Parallel to the development of assays with increasing sensitivity, interest in cardiac troponin has expanded from acute cardiac care to risk prediction and risk stratification2. **`Studies in various patient groups and asymptomatic individuals have provided compelling evidence that baseline cardiac troponin levels predict outcome3`**. Interestingly, the observed risk gradient is not restricted to elevations above the 99th percentile, but is even apparent within the ¡°healthy¡± population reference interval, and **independent of traditional risk factors such as age, sex and diabetes4¨C9.** In the Framingham heart study, the basal cardiac troponin I concentration adds prognostic value to standard risk factors for predicting death, and cardiovascular disease10. Furthermore, temporal increases in cardiac troponin concentrations over time confer additional cardiovascular risk, and are inversely related to the level of physical fitness7,11. These observations form the basis of the hypothesis that cardiac troponin is a modifiable parameter, which may be receptive to lifestyle interventions such as an exercise training program."},{"_id":"40ff1e4e4046666ff20000f0","treeId":"5fd161d2a87c2c03d5d940a9","seq":21964509,"position":5,"parentId":"41ca07f9305e62fb6e000042","content":"* The effect of exercise training on the course of cardiac troponin T and I levels: three independent training studies\n\n----与其他研究比较\n----In a recent study with (pre) frail subjects we tested the hypothesis that a supervised resistance-type exercise training program can influence the course of cardiac troponin levels over time12. However, this 24-week supervised bi-weekly exercise training program conferred no beneficial effect on the course of cardiac troponin T levels, despite substantial improvements of these subjects at the level of physical performance12. This negative study was conducted in frail and pre-frail subjects, characterized by substantially elevated baseline cardiac troponin levels, and therefore theoretically most amenable to the potential benefits of an exercise intervention. A possible drawback however, was the limited training load that could be imposed due to the level of frailty of these older subjects. Nevertheless, despite these limitations, our results were similar to those of other recent reports: 14-week endurance training in untrained adults13, 17-week half-marathon training in previously sedentary men14, and 3-month exercise training in heart failure patients (NYHA class II-IV)15 did not result reduce basal cardiac troponin T concentrations. However, limitations of these studies were the low basal cardiac troponin concentrations13 and the use of conventional instead of high-sensitive cardiac troponin T assays14,15 which reduced the power to detect an effect. Another issue that merits attention is that the effect of training intervention on cardiac troponin I has never been assessed. Since cardiac troponin T and I are two different proteins of the cardiac troponin complex with different biochemical characteristics16 and distinct release patterns17, both cardiac troponins may also respond differently to lifestyle interventions. The aim of the current study is 1) to overcome the limitations of previous studies, and 2) to examine the effect of exercise training on basal cardiac troponin I levels. Therefore, we now present two additional exercise training studies to the effect of a more intense training regimen on the course of high-sensitive cardiac troponin T and I levels in older adults, a population that often exhibits elevated basal cardiac troponin concentrations. Additional high sensitive troponin I was measured in our previously conducted study in (pre)frail subjects in order to present a complete and comprehensive overview to the effects of three supervised training programs."},{"_id":"40ff0c1e4046666ff20000f1","treeId":"5fd161d2a87c2c03d5d940a9","seq":21964521,"position":1,"parentId":"40ff1e4e4046666ff20000f0","content":"* The effect of exercise training on the course of cardiac troponin T and I levels: three independent training studies\n\n----以前是横断研究、现在看因果关系,老年人基础水平高,易受影响,避免最后一次训练的影响,证实以及扩展了以前的研究:提高了素质但cTn无影响\n----In two independent supervised training studies of 12 and 24 weeks respectively, we found no effect of resistance-type exercise training on the course of cardiac troponin T and I levels in older subjects, nor did we find an effect of a 24-week training program on cardiac troponin I levels in (pre)frail subjects. Our results do not support the idea that cardiac troponin levels might be modifiable through exercise. This hypothesis was postulated by observational studies, showing that higher physical activity levels in older subjects were associated with both lower basal cTnT levels, and a lower probability of a significant increase in cTnT concentrations between consecutive visits11,26. To investigate whether a causal relationship underlies this association, we conducted a series of training studies in subjects where stable elevated cardiac troponin levels are common, and who are therefore -at least theoretically- most receptive to the favorable effects of an intervention. To ensure that basal cardiac troponin levels, rather than acute post-exercise effects were studied, we included a three day interval between the last training session and the blood sampling procedure27. None of these studies showed a favorable effect of resistance-type exercise training on cardiac troponin levels. The non-responsive pattern of troponin T and I to an exercise program is in contrast with the beneficial changes observed for leg strength, muscle mass, insulin sensitivity, HbA1c, total cholesterol and LDL18–20,22,23. The present results confirm and extend the results of our previous training intervention study in (pre)frail older adults12, which was also characterized by favorable effects on physical performance, but a lack of effect on circulating cardiac troponin levels."},{"_id":"40fefc9f4046666ff20000f2","treeId":"5fd161d2a87c2c03d5d940a9","seq":21964540,"position":1,"parentId":"40ff0c1e4046666ff20000f1","content":"* The effect of exercise training on the course of cardiac troponin T and I levels: three independent training studies\n\n----**解释结果**:不能排除.... 但...;可能的限制,,,但。。阻力训练不是有效的手段,但耐力训练也是阴性\n----Although the absolute number of subjects in these training studies are relatively low, all studies afforded at least 90% power to detect a 10% reduction of cardiac troponin over time. We cannot exclude the possibility that training confers a smaller effect on the course of troponin levels that goes by undetected in the present study, but we feel that (much) smaller changes than specified in our power calculation would comprise limited clinical relevance. A possible limitation of our study relates to the type of exercise training intervention, comprising mostly resistance-type exercise. However the subjects’ physical state precluded (intense) endurance training. Despite the physical and metabolic improvements found in our studies18–20,22,23, a valid question may be whether resistance-type exercise training is the most appropriate type of training to generate a favorable effect on cardiac troponin concentrations. In this respect the results of a recently conducted cardio-based exercise training intervention study in heart failure patients are interesting. Similar to our studies, no favorable effect was found of a supervised endurance exercise training program on cardiac troponin T levels15."},{"_id":"40fef6954046666ff20000f3","treeId":"5fd161d2a87c2c03d5d940a9","seq":21964541,"position":1,"parentId":"40fefc9f4046666ff20000f2","content":"* The effect of exercise training on the course of cardiac troponin T and I levels: three independent training studies\n\n----高度的监控训练、带来限制、结果只适合于动机强的人\n----The supervision during the sessions contributed to the internal validity, but might also have led to increased safety, less adverse events, and a higher motivation among subjects. This may overestimate any beneficial effects of exercise training. Another point regarding the validity of our study is the participant recruitment process and study design. Since participation in the study is associated with a substantial time investment and a relatively high intensity training program, this might have attracted a specific, highly motivated subpopulation. Since our study was conducted in an elderly population we can only speculate about the effects of exercise training on basal cardiac troponin levels in younger subjects who may respond differently on exercise training and demonstrate higher cardiovascular plasticity28. Nevertheless, our study does not provide support for the hypothesis that basal cardiac troponin concentrations are receptive to a prolonged resistance-type exercise training program."},{"_id":"40fdb1abc0d8aa1fb30000fa","treeId":"5fd161d2a87c2c03d5d940a9","seq":21964724,"position":2,"parentId":"40fefc9f4046666ff20000f2","content":"* The effect of a six-month resistance-type exercise training program on the course of high sensitive cardiac troponin T levels in (pre)frail elderly\n\n----解释结果\n----The finding that the majority of participants had cTnT levels above the 99th percentile confirms our hypothesis that chronically elevated cTnT concentrations are highly prevalent among (pre)frail elderly subjects. However, despite the elevated basal levels of cTnT and the fact that subjects had not previously participated in any structured exercise program, we found no evidence for an effect of a 24-week resistance-type exercise training program on the course of cTnT levels. A possible limitation of our study is that the exercise program was based on resistance-type exercise training, and that a more endurance-type based training may have a greater effect on cTn levels. Another limitation might have been the physical state of the subjects, which precluded a higher training frequency than the biweekly program that was applied in this study. The biweekly schedule was however sufficient to induce substantial improvements of muscle strength and physical performance in this group [8,9]. In conclusion, we demonstrated that prolonged resistance-type exercise training in (pre)frail elderly does not lead to changes in the course of cTnT levels. Future studies will reveal whether more intensive and more prolonged interventions can beneficially affect the course of basal troponin levels over time."},{"_id":"41ca04bb305e62fb6e000043","treeId":"5fd161d2a87c2c03d5d940a9","seq":21978595,"position":3,"parentId":"41d01a6b6b30a8b7c200011c","content":"## LVmass\nHIAT+; CAT-\nindividual variation\n1. 尽管已经有人推测了LVmass可能是重要的影响因素,但仍没有实证研究探索。我们的随机对照的实验并不支持这个观点:HIAT与CAT都导致了cTnT的增加,但只有HIAT的LVmass增加but not in CAT,这似乎提示cTnT增加是独立于LVmass。另外,相关分析显示,两者并不相关性。\n"},{"_id":"411739c3c90d6987c60000d6","treeId":"5fd161d2a87c2c03d5d940a9","seq":21959310,"position":0.5,"parentId":"41ca04bb305e62fb6e000043","content":"* Low-volume, high-intensity, aerobic interval exercise for sedentary adults: VO₂max, cardiac mass, and heart rate recovery\n\n---- 描述结果\n----Matsuo et al. (2014) showed that an exercise program comprising an 8-week, 5-day a week, high-intensity aerobic interval training (HAIt) markedly improved maximal oxygen consumption (˙VO2max) in sedentary male subjects. the study also found that the ˙VO2max improvement in HAIt was greater than that in moderate-intensity continuous aerobic training (cAt) and that the **left ventricular (lV) mass significantly increased in HAIt, but not in cAt, **even though the exercise volume and duration of HAIt were substantially lower than of cAt. "},{"_id":"41c47fe9836b50d2f600004a","treeId":"5fd161d2a87c2c03d5d940a9","seq":21885240,"position":1,"parentId":"41ca04bb305e62fb6e000043","content":"### 本来假设,但结果却是\n* The infarct size of cardiac or skeletal muscle has been estimated by means of serial CK analysis in the blood based on the hypothesis that the amount of increase in CK is proportional to the amount of damage (2,4,11,20,24). Therefore, **it was expected that Group A** (two arms were exercised on the same day) should show an approximate two-fold increase in plasma CK compared with one exercise bout for Group B (only one arm was exercised on each bout). That is, Group A would have shown more than 5,000U/l of peak CK, since the mean peak CK value on the right and left arm bout for Group B was 2,704 U/l, and 2,501 U/l, respectively. **However**, no significant difference was found in the pattern of change and the peak CK values between Group A and Group B (either bout) (Fig. 2). In addition, the distribution of post-exercise peak CK values was similar between groups (Table 1). It should be noted that the CK response varied from subject to subject as shown in previous studies (18, 19). In this study, the subjects showed more than 25-fold (Group A) or more than 40-fold (Group B) ranges in CK response (Table!). Since the subjects were randomly placed into Group A or Group B, it seems unlikely that one of the groups consisted of more high or low CK responders. Therefore it can be assumed that the similar CK response between Group A and Group B after exercise did not happen by chance."},{"_id":"41bfbad3482816e16700004e","treeId":"5fd161d2a87c2c03d5d940a9","seq":21886608,"position":1,"parentId":"41c47fe9836b50d2f600004a","content":"**Contrary to our hypothesis**, there was no statistical difference in the incidence of response across any of the 3 SIT protocols. In addition, potential differences in biological sex were explored with no apparent sexually divergent response as males and females had similar incidences of response in aerobic capacity, aerobic performance, and anaerobic capacity (except for peak and average speed). This finding that females were more likely to be responders for time to peak speed whereas males were more likely to be responders for average speed **is surprising**. **Future work should explore this further and investigate possible mechanisms explaining these findings. **Overall, these results are **particularly important **in light of our previous research demonstrating SIT with short exercise bouts has improved psychological perceptions (Townsend et al., 2017) while maintaining several key physiological responses (Islam et al., 2017)."},{"_id":"41af5b7802146938d4000059","treeId":"5fd161d2a87c2c03d5d940a9","seq":21892929,"position":2,"parentId":"41ca04bb305e62fb6e000043","content":"### 个体差异\n* Individual patterns of response to traditional and modified sprint interval training\n--- Considering V̇ O2max is a strong independent predictor of all-cause mortality and morbidity (Kodama et al., 2009), the presence of **`heterogeneity`** in observed V̇ O2max responses to exercise training is important to understand (Bouchard et al., 1999).\n![](https://www.filepicker.io/api/file/m7St987tS5aQk2smnKP3)"},{"_id":"41116325b08e3c8e9b0000dd","treeId":"5fd161d2a87c2c03d5d940a9","seq":21960583,"position":1,"parentId":"41af5b7802146938d4000059","content":"* Exercise training and artery function in humans: nonresponse and its relationship to cardiovascular risk factors\n\n---- 个体差异;不均匀性\n----Despite the overall health benefits of exercise training, recent studies have described heterogeneous adaptations to training (28). In subjects who undertook similar exercise training interventions, some demonstrated large improvements in parameters such as cardiopulmonary fitness, blood pressure, and cholesterol, while others exhibited smaller increases or even “adverse” responses (4, 5). Such findings are consistent with anecdotal clinical observations that some individuals only respond modestly to exercise. No previous study has explored the heterogeneity of changes in artery function or health in responses to exercise training, or tried to identify predictors of training-mediated adaptations in arterial function. A widely accepted index of artery function and health is flow-mediated dilation (FMD%), the vasodilator response to an imposed shear stress stimulus following cuff-induced increases in blood flow. Recent studies indicate that brachial artery FMD% is a surrogate for the assessment of coronary artery endothelial function (30) which predicts cardiovascular outcomes in humans (11, 15, 26).\n\n----We found that \u000724% of the subjects demonstrated no change in endothelial function with training. Although no previous study has reported the heterogeneity in arterial adaptation to exercise training, recent publications by Bouchard and colleagues have raised the general concept of a lack of responsiveness to exercise training (4–6). The authors suggested that training may have an “adverse” impact on some risk factors (e.g., blood pressure, triglycerides, HDL), in certain individuals (4, 5). Whether such adverse effects translate into poor clinical outcomes is unknown, especially since CVD risk assessment is typically undertaken by examining a cluster of biomarker and/or risk factors. Nonetheless, these observations demonstrate that the effects of training are not simply unidirectional, an important message when evaluating\n"},{"_id":"4166b98622fb2a3249000087","treeId":"5fd161d2a87c2c03d5d940a9","seq":21922140,"position":3,"parentId":"41ca04bb305e62fb6e000043","content":"## 解释机制"},{"_id":"4166b8f322fb2a3249000088","treeId":"5fd161d2a87c2c03d5d940a9","seq":21922525,"position":1,"parentId":"4166b98622fb2a3249000087","content":"* Cardiac Troponin T in Healthy Full‑Term Infants\n\n---- 原因不十分清楚,几种可能的解释\n---- What causes the transient rise of cTnT in newborn infants is not fully understood. **One possible explanation could be** the transient hypoxia related to delivery, in combination with the physiological circulatory adaptation starting after birth. The circulatory adaptation continues during the first days of life which might explain the elevated values of cTnT seen several days after delivery. **It is not clarified at what time point cTnT reaches its highest levels postnatally nor** when it equals adult reference values."},{"_id":"4125866171622f36800000c7","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954481,"position":4,"parentId":"41ca04bb305e62fb6e000043","content":"## LVmass+VO2max一起讨论\n\n\"This study demonstrated that 6 wk of HIIT but not MICT lowered cardiac afterload...\""},{"_id":"4125850071622f36800000c8","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954338,"position":1,"parentId":"4125866171622f36800000c7","content":"* High-Intensity Interval Training Improves Left Ventricular Contractile Function\n\n----HIT和MCT的不同效应,以及与其他研究的比较\n---- Echocardiographic strain/SR analysis is a new noninvasive method for the early detection of segmental myocardial dysfunction (13). **In this longitudinal study, HIIT simultaneously enhanced the radial strain/SR in basal and apical segments, whereas MICT only increased the radial strain/SR in the apical segment.** Eun et al. (15) and Charfeddine et al. (26) have reported that endurance athletes exhibited greater circumferential strain at the basal segment and radial/circumferential strains at the apical segment than did healthy untrained subjects. These previous findings (15,26) were consistent with part of our results. However, these previous investigations were cross-sectional studies (15,26), that the favorable cardiac functions among the well-trained athletes may be only partially attributable to physical training, and that the influence of genetic selection or differences in other characteristics between groups cannot be excluded. "},{"_id":"4124fe3e71622f36800000cb","treeId":"5fd161d2a87c2c03d5d940a9","seq":21957070,"position":5,"parentId":"41ca04bb305e62fb6e000043","content":"## LVmass 单独讨论\n“This study demonstrated that 6 wk of HIIT but not MICT lowered cardiac afterload…” 这是由于心肌肥大的幅度取决于强度、MCT没有效果可能是训练频率低,应达到每周5次。\n\n"},{"_id":"4124fd9b71622f36800000cc","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954564,"position":1,"parentId":"4124fe3e71622f36800000cb","content":"* High-Intensity Interval Training Improves Left Ventricular Contractile Function\n\n----描述主要发现\n---- Typically, the exercise training effect on cardiac function is assessed by M-mode in echocardiography, which only displays the size of ventricular cavity, myocardial thickness, the integrity of interventricular septum, and the motion of ventricular wall at rest (8). The present study further contributes to a greater understanding of LV mechanical responses to various exercise regimens using stress echocardiography. In summary, HIIT for 6 wk induces eccentric myocardial hypertrophy, enhances myocardial performance, and reduces peak torsion to reduce energy consumption for myocardial contraction, thereby improving LV contractile function. On the other hand, this exercise regimen also improves diastolic function by increasing the Vp and the E/A ratio as well as reducing the time to reach peak untwisting velocity, consequently increasing SV. **Although MICT modestly elevates myocardial contractility, cardiac diastolic function `remains unchanged after this exercise intervention`.** The present findings provide a new insight into the superior effects of HIIT on LV mechanics during exercise by simultaneously increasing contractile and diastolic functions and may have important implications for exercise training in cardiac rehabilitation."},{"_id":"411f53194f594eef4f0000d1","treeId":"5fd161d2a87c2c03d5d940a9","seq":21957037,"position":2,"parentId":"4124fe3e71622f36800000cb","content":"* High-Intensity Interval Training to Maximize Cardiac Benefits of Exercise Training?\n\n---- 细胞水平上,心肌肥大幅度取决于运动强度\n----High-intensity exercise training at 85%Y90% of V? O2max induces a hypertrophic response in the cardiomyocytes that is observable already after a few weeks and reaches a plateau after approximately 2 months (16,17,31). The magnitude of cardiomyocyte hypertrophy depends on the intensity of exercise because high-intensity exercise training induced a substantially larger response than moderate intensity: 14% versus 5% longer cells, respectively (16).\n"},{"_id":"412509f471622f36800000c9","treeId":"5fd161d2a87c2c03d5d940a9","seq":21957075,"position":3,"parentId":"4124fe3e71622f36800000cb","content":"* High-Intensity Interval Training Improves Left Ventricular Contractile Function\n\n----**解释MICT没有引起LVmass增加:训练量小**\n---- On the other hand, we speculate that the exercise volume of MICT in this study might be too low to exert any positive effects on cardiac hemodynamic adaption in these subjects. The majority of the positive MICT studies applied the exercise training at least 5 d穡k-1 up to six times daily for a period of at least 12 wk (37). As in numerous other investigations, a limitation of this study is that the subjects tended to be young and healthy. Thus, additional clinical evidence is required to extrapolate the present results to patients with abnormal cardiovascular systems, such as patients with myocardial ischemia or heart failure."},{"_id":"4117d622826f1388b60000d3","treeId":"5fd161d2a87c2c03d5d940a9","seq":21959174,"position":1,"parentId":"412509f471622f36800000c9","content":"* Effects of a low-volume aerobic-type interval exercise on VO2max and cardiac mass\n\n---- 训练时间频率不足,造成MCT对LVmass无影响。\n----Cardiac MRI revealed that an 8-wk (five times per week), 40-min, traditional, moderate-intensity continuous exercise (the CAT) had no significant impact on myocardial mass. Two previous studies (19,30) using the MRI method showed increases of 8.2% and 5.5% in LV mass after 3 months of endurance training (bicycle ergometer and jogging, respectively). Another MRI study by Spence et al. (31) also showed a significant 8.3% increase in LV mass after 6 months of exercise training, although their exercise protocol included walking, running, hill running, and short intervals. **Compared with these studies (19,30,31), our CAT exercise period (8 wk) may have been `relatively short for detecting a significant increase in LV mass`.** Conversely, although the exercise volumes of interval exercises in our study were small, LV mass increased with both sprint- and aerobic-type interval training. Moreover, percentage changes in SV and HR were significant in both SIT and HIAT (Fig. 3)."},{"_id":"410aa4bd251346d6e90000e0","treeId":"5fd161d2a87c2c03d5d940a9","seq":21961639,"position":0.5,"parentId":"4117d622826f1388b60000d3","content":"* Left ventricular function after exercise training in young men\n\n---- 需要更长的训练才能引起LVmass增加,6个月\n\n"},{"_id":"4116c6adc90d6987c60000d8","treeId":"5fd161d2a87c2c03d5d940a9","seq":21959377,"position":1,"parentId":"4117d622826f1388b60000d3","content":"* Low-volume, high-intensity, aerobic interval exercise for sedentary adults: VO₂max, cardiac mass, and heart rate recovery\n\n---- 描述结果\n----However, our study also showed that the improved Hrr was not observed in the cAt group even though their V ˙ O2max significantly increased after intervention. Sugawara et al. (2001) demonstrated that Hrr improved after cAt intervention consisting of 8-week, 3–4 days/week, continuous cycling exercise for 60 min at 70 % ˙VO2max in healthy, untrained male subjects. the exercise **intensity and duration of our cAt (60–65 % ˙VO2max, 40 min) might be relatively lower** for improving Hrr than in their study (Sugawara et al. 2001). "},{"_id":"41ca0064305e62fb6e000044","treeId":"5fd161d2a87c2c03d5d940a9","seq":21961606,"position":4,"parentId":"41d01a6b6b30a8b7c200011c","content":"## Correlation\ncTnT vs. LVmass -\n\n**An unexpected finding of the present study was** however the thinning of ST and PWT after training."},{"_id":"41a39d2582f21f5e8a000062","treeId":"5fd161d2a87c2c03d5d940a9","seq":21927643,"position":2,"parentId":"41ca0064305e62fb6e000044","content":"## 描述 不相关"},{"_id":"4155640d65ab5d79ac00009f","treeId":"5fd161d2a87c2c03d5d940a9","seq":21930099,"position":0.125,"parentId":"41a39d2582f21f5e8a000062","content":"* Magnitude, Reproducibility, and Association With Baseline Cardiac Function of Cardiac Biomarker Release in Long-Distance Runners Aged >55 Year\n\n---- 宽的数据范围,适合做相关\n---- The exertional release of NT¨CproBNP was highly associated with its baseline levels. Although this relation may appear obvious, it has never actually been reported previously. This age group may constitute a particularly useful sample for studying this association, because NT¨CproBNP levels showed **`relatively wide dispersion`**, including 5 subjects with pathologic levels already at baseline."},{"_id":"4116b974c90d6987c60000d9","treeId":"5fd161d2a87c2c03d5d940a9","seq":21959382,"position":1,"parentId":"4155640d65ab5d79ac00009f","content":"* Low-volume, high-intensity, aerobic interval exercise for sedentary adults: VO₂max, cardiac mass, and heart rate recovery\n\n---- 描述不相关,意味着什么?\n-------In the present study, we found **no significant correlations between **Hrr values and cardiac MrI values (data not shown), i.e., **the study did not detect any associations** between changes in Hrr and cardiac functions induced by exercise training. "},{"_id":"4198f0bc6de926ef3000006d","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954185,"position":0.25,"parentId":"41a39d2582f21f5e8a000062","content":"### 引言,背景\n* Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart\n\n---- 结构与生化的联系 理解很少\n---- While these structural and functional attributes of exercise-induced cardiac remodeling have been thoroughly delineated (3), the biochemical correlates of this process are not yet fully understood.\n\n---- 训练及伴随的心脏塑性对cTn影响,仍未研究\n----To date, the vast majority of periexercise cTnT data describe single exercise bouts (23, 27), and thus the potential impact of ET and attendant cardiac remodeling on cTnT has not been examined.\n\n----运动心肌塑性的生化特征知之甚少,本研究对此有贡献\n----At present, the biochemical characteristics of EICR are less comprehensively understood and findings from the current study advance our understanding of this element of cardiac plasticity in several ways.\n----**Longitudinal data with** pre- and post-ET measurements confirm prior **cross-sectional** studies (1, 24, 31) suggesting that EICR does not result in increased NPs under resting conditions. Similarly, our data suggest that cTnT levels, both at rest and after brief bouts of maximal effort exercise, **are unaffected by endurance ET.** In addition to these confirmatory findings, we now show that endurance ET with corollary EICR results in an attenuated NP response to acute bouts of maximal intensity exercise."},{"_id":"4166b2ad22fb2a324900008b","treeId":"5fd161d2a87c2c03d5d940a9","seq":21922144,"position":1,"parentId":"4198f0bc6de926ef3000006d","content":"* Cardiac Troponin T in Healthy Full‑Term Infants\n\n---- 以前的研究,仍存在的空白\n---- Several studies have investigated cTnT values in infants after admission for neonatal care [3¨C5, 10¨C24]. Only a limited number of studies have determined cTnT values primarily in healthy full-term infants [1, 2, 25¨C28]. All but one of these studies have been performed before the introduction of hs-cTnT assays [2] and a considerable proportion of cTnT values were even below the detection limit [1, 25]. Cardiac troponin T has in most cases been determined either in cord blood [1, 2, 25, 26, 28] or in peripheral blood [3, 11¨C13, 17¨C19, 21, 29]. Only a few studies have done sequential measurements of cTnT, and primarily in asphyxiated or premature infants [5, 10, 16]. We aimed to investigate hs-cTnT values in cord blood and during the first week of age, in healthy full-term infants born either after spontaneous onset of delivery, or after planned caesarean section (CS). We hypothesized that hs-cTnT would be elevated already in cord blood, compared with the adult upper reference limit, and that it would further increase over the first 2¨C5 days of age. We finally hypothesized that hs-cTnT values would be higher in infants born after vaginal delivery compared with infants born after planned CS"},{"_id":"416128c2ffcb296715000091","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954160,"position":1,"parentId":"4166b2ad22fb2a324900008b","content":"* Metabolic syndrome is associated to high-sensitivity cardiac troponin T elevation\n\n--- 研究有限;不一致;本研究的优势:\n---Data regarding the association between highly sensitive troponin and MetS are limited. In both children and adults, there is disagreement on whether obesity per se or metabolic abnormalities are the cause of increased hs-TnT (Pervanidou et al. 2013, Zeng et al. 2016). In adults, reports from a relatively small sample in Japan found no significant association between MetS and hs-TnT (Hitsumoto and Shirai 2015). However, recent evidence from a sub-analysis of the ARIC (Atherosclerosis Risk in Communities) study showed a significant association between MetS and hs-TnT (Pokharel et al. 2017). Our results in a relatively large cohort are in line with those of the ARIC sub-analysis. In addition, the observed association between male gender and hs-TnT concur with the ARIC sub-analysis and a large recent meta-analysis including 154,052 participants assessing predictors for hs-Tn elevation (Pokharel et al. 2017, Willeit et al. 2017)."},{"_id":"41a3c45482f21f5e8a000060","treeId":"5fd161d2a87c2c03d5d940a9","seq":21897597,"position":0.5,"parentId":"41a39d2582f21f5e8a000062","content":"* Immediate and 24-h post-marathon cardiac troponin T is associated with relative exercise intensity\n\n---- **与预期相反:不相关**\n----However, contrary to our expectations, baseline echocardiographic and cardiovascular fitness variables were not associated with hs-TNT rise and normalization, except for a small association between LVESD and post-race hs-TNT values, which seems clinically unimportant."},{"_id":"41596dbe486e3540a800009d","treeId":"5fd161d2a87c2c03d5d940a9","seq":21928725,"position":1,"parentId":"41a3c45482f21f5e8a000060","content":"* Predictors of cardiac troponin release after a marathon\n\n--- 支持、与不支持的研究,相关性\n--- We also observed a positive relationship between exercise duration and post-race cTnI levels. Although this finding is in line with some of the recent field and laboratory studies,8,9 others have reported an opposite relationship between post-race cTnI levels and exercise duration.20,23 These latter studies suggest that longer exercise duration is usually related to lower exercise intensity, and consequently to a lower increase in exercise-induced cTnI levels.20,24 **In our study, participants did not demonstrate a relation between finish time and exercise intensity (r = 0.11, p = 0.36). ** `Given the` homogeneous exercise intensity in our population, participants with longer exercise duration were exposed to higher cardiac stress. The release of exercise-induced cTnI levels in participants with longer exercise duration may therefore relate to the higher cardiac work. However, it must be emphasized that future studies should further examine whether troponin-release after exercise relates to absolute cardiac work, independent of exercise type."},{"_id":"4126016a71622f36800000c2","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954234,"position":2,"parentId":"41a3c45482f21f5e8a000060","content":"* Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart\n\n---- 结果:LVmass+,restingcTnT=, VO2max+\n尽管cTnT=,但仍支持LVmass与cTnT无相关性"},{"_id":"41c46d34836b50d2f600004b","treeId":"5fd161d2a87c2c03d5d940a9","seq":21960551,"position":1,"parentId":"41a39d2582f21f5e8a000062","content":"* Relationship between Post-Exercise Plasma CK Elevation and Muscle Mass Involved in the Exercise\n\n---描述不相关\n----In summary, the results of this study did **not find a relationship** between the magnitude of post-exercise plasma CK and muscle mass affected by an eccentric exercise. **It is quite remarkable** that subjects who exercised two arms would have very similar CK responses as those exercising only one arm. It is concluded that the amount of CK increase after exercise does not necessarily indicate the amount of muscle damaged"},{"_id":"4155365265ab5d79ac0000a0","treeId":"5fd161d2a87c2c03d5d940a9","seq":21930146,"position":1,"parentId":"41c46d34836b50d2f600004b","content":"* Impact of an endurance training program on exercise-induced cardiac biomarker release\n\n---- 讨论 安静值高 **讨论相关**\n---- We observed higher baseline and peak postexercise values for hs-cTnT after 14 wk of running training, which also differentiated this group from the control cohort. This supports some previous cross-sectional data from athletes of different training status (Legaz-Arrese et al., unpublished observations; and Ref. 24) but does contradict past field-based studies of runners with higher and lower selfreported training volumes (e.g., Ref. 20). The assay precision and method used to quantify the level of training may also be confounding factors in the relationship observed in previous studies. In the largest case series data in marathoners, Fortescue et al. (5) noted that the runners with less prior experience in marathon running were more likely to have cTnT increases. They also found no relationship between race time and the increase in cTnT, suggesting that the number of previous marathons may not be the most appropriate way to quantify the current level of training. Furthermore, the authors indicated no significant relationship between the release of cTnT and average training pace or average miles run per week during the last 3 mo. In the same direction, a multiple regression analysis demonstrated that marathon experience was a significant predictor of postmarathon hs-cTnT (19). Once again, the authors did not establish a relationship between marathon time and the release of hs-cTnT and did not gather other data on the level of training of the athletes. The association observed by Nie et al. (21) and Tian et al. (39) between the number of years of training and cTnT or cTnI release after a half-marathon in adolescent subjects was weak and could have been influenced by the maturity status of the adolescents. Moreover, in neither of these studies did the authors observe a relationship for other indicators of the level of training, such as weekly training distance. Finally, using a prospective study design, Mehta et al. (15) revealed that average miles run per week in the last 3 yr (an indicator of previous training experience) was negatively associated with postmarathon cTnI release. No association, however, was observed for the current training status (miles run per week in the last 4 mo) or for race time"},{"_id":"4111674cb08e3c8e9b0000dc","treeId":"5fd161d2a87c2c03d5d940a9","seq":21960554,"position":2,"parentId":"41a39d2582f21f5e8a000062","content":"* Exercise training and artery function in humans: nonresponse and its relationship to cardiovascular risk factors\n\n---- 描述相关;\n----We found that cardiopulmonary fitness improved, and weight, body mass index (BMI), cholesterol, and mean arterial pressure (MAP) decreased after training, while FMD% increased in 76% of subjects (P 0.001). \n---With the exception of a modest correlation with total cholesterol (r \u0004 \u00050.243, P 0.01), changes in traditional cardiovascular risk factors were not significantly related to changes in FMD% (P \u0006 0.05). \n----exercise training-induced change in FMD% did not correlate with changes in traditional cardiovascular risk factors, indicating that some cardioprotective effects of exercise training are independent of improvement in risk factors."},{"_id":"41a39a0082f21f5e8a000063","treeId":"5fd161d2a87c2c03d5d940a9","seq":21930194,"position":3,"parentId":"41ca0064305e62fb6e000044","content":"## 解释 不相关\n横断研究显示相关:缺乏急性运动的影响;横断研究老年人多病理肥大,而本研究属于生理性肥大?"},{"_id":"41a398d582f21f5e8a000064","treeId":"5fd161d2a87c2c03d5d940a9","seq":21897609,"position":1,"parentId":"41a39a0082f21f5e8a000063","content":"* Immediate and 24-h post-marathon cardiac troponin T is associated with relative exercise intensity\n\n---- 解释为何不相关\n----The absence of a relationship between post-race hs-TNT levels and self-reported training history was also observed by (Kleiven et al. 2019). However, this observation differs from results of other previous studies (Fortescue et al. 2007; Kosowski et al. 2019; Mehta et al. 2012; Neilan et al. 2006), where cardiac troponin release was inversely associated with training experience and weekly training mileage. Our sample was maybe more homogeneous in relation to training status compared to the previous studies, because of our narrow inclusion criteria. This fact could explain why no relationship was identified between post-race hs-TNT values and self-reported training history. On the other hand, the lack of any association between post-race hs-TNT levels and baseline CPET variables (i.e., VO2max, peak speed and speed attained at VT2) concurs with previous studies (Kosowski et al. 2019; Richardson et al. 2018; Trivax et al. 2010). Similarly, our results also coincide with the preceding investigations, which showed a lack of correlation between echocardiographic measures and hs-TNT release after exercise (Donaldson et al. 2019; Kosowski et al. 2019; Paana et al. 2019)"},{"_id":"4104fbc6dd6f92fd2e0000e4","treeId":"5fd161d2a87c2c03d5d940a9","seq":21962952,"position":1,"parentId":"41a398d582f21f5e8a000064","content":"\n* Relation of Lifestyle Factors and Life’s Simple 7 Score to Temporal Reduction in Troponin Levels Measured by a High-Sensitivity Assay (from the Atherosclerosis Risk in Communities Study)\n\n----我们没有发现,cTn与LVmass的联系;可能的解释是:\n----In the current study, we did not find an association between healthy diet score and reversal of subclinical myocardial damage. One possible explanation is that the cardioprotective effects of a healthy diet are not realized in the short, 6-year follow-up of our study. Moreover, we carried forward the visit 1 dietary information, which may not best reflect diet at visit 2. The 5 components of the healthy diet score of the AHA LS7 and the thresholds used to dichotomize the population as meeting criteria may not fully represent diet quality that are relevant for cardiovascular health. Additionally, the food frequency questionnaire, which was administered in the ARIC study, is not the ideal dietary assessment instrument for quantifying absolute intake of sodium.24 We also did not find an association between moderate alcohol consumption and incident undetectable hs-cTnT.\n\n---解释为何大样本研究发现了相关\n---Our finding showed that current smoking may have a “protective,” although nonsignificant, effect on subclinical myocardial damage in our main analysis; we observed a strong association between current smoking and risk of all-cause mortality during our study follow-up (Supplementary Table S2), **suggesting that the observed inverse association between current smoking and hs-cTnT may be influenced by survival bias or reverse causality**. This inverse association is consistent with several previous studies.6,25 It has been postulated that smoking may reduce cardiac myocyte turnover and immune mediated myocardial remodeling, reflected in lower levels of circulating troponins.26 Additionally, given that smoking is associated with lower BMI,27 our counterintuitive results may be in part mediated by the impact of smoking on reduced BMI, which is associated with decreased likelihood of incident myocardial damage.\n"},{"_id":"4103e74963376d0ba30000e8","treeId":"5fd161d2a87c2c03d5d940a9","seq":21963010,"position":1,"parentId":"4104fbc6dd6f92fd2e0000e4","content":"* The effects of exercise on cardiovascular biomarkers in patients with chronic heart failure\n\n---- 我们的纵向研究,横断研究的缺点:假阳性联系\n----Lastly, an observational study of 2,933 patients with HF looked at the effects of physical activity on NT-proBNP levels, finding evidence of an inverse relationship between NT-proBNP levels and amount of self-reported physical activity.17,18 Our results confirm the negative correlation between volume of exercise and biomarker levels, but not an association between exercise training and improvements in biomarker levels. This implies that the suggested causal relationship between activity and lower NT-proBNP levels may have resulted from false-positive associations, a common drawback of observational studies.17"},{"_id":"419c8635e7d3819fe2000069","treeId":"5fd161d2a87c2c03d5d940a9","seq":21899811,"position":2,"parentId":"41a39a0082f21f5e8a000063","content":"* High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014\n\n----解释机制\n----Although the performance-enhancing effects of nicotine are unlikely to explain the differences observed, higher myocardial perfusion as a consequence of nicotine use **could be a possible mechanism for** lower circulating concentrations of cTn in snus users.\n----Associations between smoking and improved short-term outcomes have been described for several cardiovascular disorders.30¨C32 The mechanisms underlying the ¡°smokers¡¯ paradox¡± **are unknown, but a possible explanation could be that tobacco protects myocytes by **preconditioning.31,32 Whether this apparently cardioprotective effect of smoking also holds true for snus is unknown. Furthermore, if the smokers¡¯paradox is the result of the biological effects of tobacco or could be explained by selection and/or unmeasured bias is an ongoing discussion.30,33"},{"_id":"4166b81c22fb2a3249000089","treeId":"5fd161d2a87c2c03d5d940a9","seq":21922527,"position":3,"parentId":"41a39a0082f21f5e8a000063","content":"* Cardiac Troponin T in Healthy Full‑Term Infants\n\n---- 原因不十分清楚,几种可能的解释\n---- What causes the transient rise of cTnT in newborn infants is not fully understood. **One possible explanation could be** the transient hypoxia related to delivery, in combination with the physiological circulatory adaptation starting after birth. The circulatory adaptation continues during the first days of life which might explain the elevated values of cTnT seen several days after delivery. **It is not clarified at what time point cTnT reaches its highest levels postnatally nor **when it equals adult reference values."},{"_id":"415aae69ff62e93dca00009a","treeId":"5fd161d2a87c2c03d5d940a9","seq":21927774,"position":0.5,"parentId":"4166b81c22fb2a3249000089","content":"* Sex influence on myocardial function with exercise in adolescents\n\n--- 可能受到了衰老及心脏病理的影响\n--- Previous investigations in **middle- to older age populations** may have been influenced by the aging process itself as well as occult coronary disease. This study assessed myocardial performance in an earlier phase of sexual maturity to eliminate such influences."},{"_id":"4154864065ab5d79ac0000a2","treeId":"5fd161d2a87c2c03d5d940a9","seq":21930201,"position":1,"parentId":"415aae69ff62e93dca00009a","content":"* Physiological and pathological left ventricular hypertrophy of comparable degree is associated with characteristic differences of in vivo hemodynamics\n\n----病理性心脏肥大 与 生理性心肌肥大"},{"_id":"414bf33838e64a8eda0000a6","treeId":"5fd161d2a87c2c03d5d940a9","seq":21936232,"position":1,"parentId":"4154864065ab5d79ac0000a2","content":"* High sensitivity cardiac troponins: Can they help in diagnosing myocardial ischaemia?\n\n--- LVH 影响cTn值\n--- In a recent study evaluating the impact of LVH on troponin release during myocardial infarction, it was estimated that the peak of hs-cTnI overestimates infarct size by approximately 30% in the presence of LVH.26 However, even more critical is the issue of small increments of troponin in patients with chest pain and LVH, given the **high prevalence (20–25%) of LVH in the general population**26 and the possibility of false-positive diagnoses of myocardial infarction in this setting. In addition, small increments in circulating troponin I27 and T28 have been reported, in patients with LVH, even in the absence of chest pain and any other acute pathology. \n\n----机制\n----Left ventricular hypertrophy enhances troponin release by means of multiple mechanisms. The first cause is simply a greater content of troponin (both structurally bound to contractile apparatus and in a free cytosolic pool, see below) in hypertrophied cardiomyocytes.26 However, the most important mechanism explaining minor and transient increments of troponin in patients without myocardial infarction is probably coronary microvascular dysfunction associated with LVH, which impairs coronary vasodilator reserve and predisposes to stress-induced myocardial ischaemia, also in absence of obstructive CAD.29 "},{"_id":"414afbfe7715c922ab0000aa","treeId":"5fd161d2a87c2c03d5d940a9","seq":21936891,"position":2,"parentId":"4154864065ab5d79ac0000a2","content":"*Association of Troponin T Detected With a Highly Sensitive Assay and Cardiac Structure and Mortality Risk in the General Population\n\n--- LVH与其他心血管病相联系\n--- However, our data showing associations with LVH and other cardiac structural abnormalities as well as with mortality among individuals classified at low risk using the FRS suggest that low levels of cTnT may identify subclinical structural heart disease and contributors to cardiovascular disease risk not fully captured by current riskassessment tools. .\n--- **`老年人、病理LVH 更高的安静cTnT`**\n![](https://www.filepicker.io/api/file/UzwBXm5WQuuFK2sj4Qel)\n![](https://www.filepicker.io/api/file/dUg4idiQ0GWIM7FoJfnO)"},{"_id":"4132ab047eeb97844d0000b8","treeId":"5fd161d2a87c2c03d5d940a9","seq":21947496,"position":1,"parentId":"414afbfe7715c922ab0000aa","content":"* Association of Novel Biomarkers of Cardiovascular Stress With Left Ventricular Hypertrophy and Dysfunction: Implications for Screening\n\n---- 大样本、cTn与LVH相关;2460 Framingham Study;平均年龄58岁"},{"_id":"41224157cbc76f03b10000d0","treeId":"5fd161d2a87c2c03d5d940a9","seq":21955813,"position":2,"parentId":"414afbfe7715c922ab0000aa","content":"* Association of Troponin T Detected With a Highly Sensitive Assay and Cardiac Structure and Mortality Risk in the General Population(#414)\n\n---- 老年人,cTnT与LVmass相关,病理原因\n----"},{"_id":"4145d436771f58ce700000ab","treeId":"5fd161d2a87c2c03d5d940a9","seq":21939086,"position":3,"parentId":"4154864065ab5d79ac0000a2","content":"*An association between volumes of the cardiac chambers and troponin levels in individuals submitted to cardiac coronary computed tomography\n\n--- 在老年人, 心脏四个腔的容量与cTnI相关"},{"_id":"4125d20371622f36800000c5","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954283,"position":2,"parentId":"415aae69ff62e93dca00009a","content":"* Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart\n\n---- 生理性心肌肥大与病理性心肌肥大在生化上有区别\n---- Plasma B-type NP levels are typically increased under resting conditions among patients with pathologic ventricular hypertrophy (38). Similarly, resting levels of A-type NPs are driven by LA size in the setting of cardiovascular pathology (7, 10). In contrast, resting levels of B-and A-type NPs are similar among endurance athletes with EICR and healthy normally active controls (1, 24, 31). **This suggests that physiologic hypertrophy has different biochemical characteristics than pathologic hypertrophy.** Release of NPs during exercise has been well documented in cross-sectional studies across diverse populations with the magnitude of response determined by exercise intensity, exercise duration (23, 31, 37), and the presence or absence of myocardial disease (21, 38). Specifically, exercise duration appears to be a key determinant of BNP release while exercise intensity appears to be the predominant stimulus for ANP release (15)"},{"_id":"41246d3e71622f36800000ce","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954756,"position":1,"parentId":"4125d20371622f36800000c5","content":"* Association of Serial Measures of Cardiac Troponin T Using a Sensitive Assay With Incident Heart Failure and Cardiovascular Mortality in Older Adults\n\n----老年人群病理性心肌肥大,cTnT升高\n---- Ischemia from known or unknown coronary artery disease must be considered in an older population, but magnetic resonance imaging in another stable older population does not support chronic ischemic heart disease as a predominant etiology linking low levels of troponins with subsequent development of HF.30"},{"_id":"415b1226507e3246ef000098","treeId":"5fd161d2a87c2c03d5d940a9","seq":21936231,"position":1,"parentId":"4166b81c22fb2a3249000089","content":"* Prevalence and determinants of troponin T elevation in the general population\n\n--- LVmass 病理性心肌肥大 导致cTn升高的,可能机制\n--- Troponin elevation seen with LVH may be the result of **a supply/demand mismatch** whereby hypertrophied myocytes physically impair adequate endocardial\ntissue perfusion.36 "},{"_id":"412bd31c6721a5afde0000be","treeId":"5fd161d2a87c2c03d5d940a9","seq":21950985,"position":1,"parentId":"415b1226507e3246ef000098","content":"* High-Sensitive Cardiac Troponin for Prediction of Clinical Heart Failure\n\n---- LVH与cTn相关 机制\n----Hs-cTn elevation may be caused by multiple mechanisms, in addition to myocardial necrosis. These include cardiomyocyte damage from inflammatory cytokines or oxidative stress, apoptosis, increased cell membrane permeability induced by increased stretch or stress with troponin release by injured but still viable cells, fragmentation of altered troponins with release into the circulation of fragments with an affinity for the troponins immunoassays, and production of membranous blebs containing troponins that could release them in the bloodstream.5 Thus, hs-cTn release may not only occur in the setting of myocardial injury related to atherosclerotic coronary heart disease but may be also **an expression of other structural phenotypes correlated to HF risk, such as increased LV mass.3**"},{"_id":"412f3b0d3be8fa3e840000bb","treeId":"5fd161d2a87c2c03d5d940a9","seq":21950121,"position":2,"parentId":"4166b81c22fb2a3249000089","content":"* Association of novel biomarkers of cardiovascular stress with left ventricular hypertrophy and dysfunction: implications for screening\n\n---- 年龄增加血压增加,三分之一的人并不知道血压高、血压高引起LVH、病理性LVH?\n----Given the high prevalence of LVH in the general population (20% to 25%),11,12 and especially in the MI population (50%),27 it is of great importance to know whether LV mass affects the systemic release of biomarkers after an AMI. Notably, stratification according to hypertension—the most frequent cause of LVH—may be insufficient to control the effect of LV mass on biomarker release, given that **approximately one-third of patients with hypertension are unaware that they are hypertensive**.28"},{"_id":"412ef2923be8fa3e840000bc","treeId":"5fd161d2a87c2c03d5d940a9","seq":21950122,"position":3,"parentId":"4166b81c22fb2a3249000089","content":"* Association of novel biomarkers of cardiovascular stress with left ventricular hypertrophy and dysfunction: implications for screening\n\n---- 肥大的心肌释放了更多的cTnI, 但肥大并不影响CK释放量;直觉推测认为心肌细胞cTn含量会随着心肌肥大而增加,因为cTn随着心肌细胞收缩单位和相关收缩蛋白含量普遍增加而增加。\n----Our analysis of total CK and cTnI showed that whereas hypertrophied hearts release more cTnI than control hearts upon AMI, hypertrophy does not affect total CK release. The CK system is important for intracellular energy production and utilization and is abundantly present in tissues with high metabolic demand. There are 4 electrophoretically distinct CK isoenzymes—BB, MB, MM, and the mitochondrial forms (mi-CK)—with CK-MB predominating in the adult heart.29 Animal models of LVH consistently show that hypertrophic cardiomyocytes switch to a fetal CK isoenzyme pattern, increasing expression of CK-MB and CK-BB at the expense of reduced expression of CK-MM and mi-CK in order to increase energy yield; these changes balance out so that total CK levels in the hypertrophied myocardium are unaltered.30–35 In contrast, it is intuitive to argue that cardiomyocyte content of troponin would increase with hypertrophy as part of the general increase in cardiomyocyte content of contractile units and associated contractile proteins. Thus, in the setting of LVH, the release of troponins will be disproportionally high after STEMI, whereas total CK release will not be affected."},{"_id":"419cb9d6e7d3819fe2000064","treeId":"5fd161d2a87c2c03d5d940a9","seq":21927644,"position":4,"parentId":"41ca0064305e62fb6e000044","content":"## 本研究的贡献"},{"_id":"419cb74ce7d3819fe2000065","treeId":"5fd161d2a87c2c03d5d940a9","seq":21899786,"position":1,"parentId":"419cb9d6e7d3819fe2000064","content":"* High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014\n\n----本研究的贡献\n----In the current study, we add to the existing knowledge by providing data on the associations between snus tobacco and the exercise-induced troponin response. Our results indicate that substances in tobacco may modulate the acute release and/or degradation of cTn in the exercise-induced release setting."},{"_id":"416118edffcb296715000092","treeId":"5fd161d2a87c2c03d5d940a9","seq":21926541,"position":1,"parentId":"419cb74ce7d3819fe2000065","content":"* Metabolic syndrome is associated to high-sensitivity cardiac troponin T elevation\n\n--- 本研究支持...观点,并进一步有贡献\n---The findings of the ARIC sub-analysis suggest that hs-TnT testing can further refine risk stratification in patients with MetS. Our results corroborate this concept in that it establishes not only an association between Mets and hs-Tn but suggests a continuous relation between the metabolic burden (i.e. the number of MetS components) and hs-TnT in asymptomatic subjects."},{"_id":"419855a16de926ef30000072","treeId":"5fd161d2a87c2c03d5d940a9","seq":21900368,"position":2,"parentId":"419cb9d6e7d3819fe2000064","content":"* Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart\n\n---- 训练 心肌塑性 生化联系 细胞机制\n---- Remodeling in our cohort was characterized by an ~7% increase in LV wall thickness but only a 3% increase in LV chamber radius, a pattern that does not only preserve, but actually reduces cardiac wall stress during maximal effort exercise. This observation underscores the true adaptive nature of EICR and for the first time provides objective biochemical correlates. Complementary underlying cellular mechanisms including downregulation of NP synthesis and/or attenuated release in response to pressure/volume mechanotransduction are likely responsible. Future work will be required to define the precise cellular pathways that underlie ET-induced downregulation of the NP response to acute bouts of exercise."},{"_id":"41982e2a6de926ef30000077","treeId":"5fd161d2a87c2c03d5d940a9","seq":21900411,"position":1,"parentId":"419855a16de926ef30000072","content":"* Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart\n\n---- 结论、总结、贡献\n---- In summary, rowing-based ET and corollary EICR appear to result in an attenuated NP response to maximal effort exercise. While mechanisms remain speculative, our data suggest that this occurs as a function of disproportionally higher ventricular wall thickening compared with chamber dilation. In aggregate, **these observations advance our understanding of the interplay between** structural and biochemical adaptations that underlie the cardiovascular response to ET."},{"_id":"4103da3663376d0ba30000e9","treeId":"5fd161d2a87c2c03d5d940a9","seq":21963018,"position":3,"parentId":"419cb9d6e7d3819fe2000064","content":"* The effects of exercise on cardiovascular biomarkers in patients with chronic heart failure\n\n---- 不是一个可靠的指标\n----Although inflammation and myonecrosis play a central role in the pathogenesis of chronic HF, only a handful of studies have reported on changes in hs-CRP and cTnT with exercise in patients. These studies have not included patients with established HF; to our knowledge, this is the first look at the effects of exercising training on serial hsCRP and cTnT levels in this patient population.19-22 **Our results suggest that serial measurements of these biomarkers may not be reliable surrogates for any health benefits of physical activity in this patient population.**"},{"_id":"41c9f927305e62fb6e000045","treeId":"5fd161d2a87c2c03d5d940a9","seq":21881688,"position":5,"parentId":"41d01a6b6b30a8b7c200011c","content":"## Implications"},{"_id":"41050238dd6f92fd2e0000e2","treeId":"5fd161d2a87c2c03d5d940a9","seq":21962948,"position":0.125,"parentId":"41c9f927305e62fb6e000045","content":"* Relation of Lifestyle Factors and Life’s Simple 7 Score to Temporal Reduction in Troponin Levels Measured by a High-Sensitivity Assay (from the Atherosclerosis Risk in Communities Study)\n\n---- 观察,生活方式影响 cTnT 有什么价值\n----Cardiac troponin is a standard biomarker used to diagnose myocardial infarction in the setting of chest pain. New highly sensitive assays for cardiac troponin can detect concentrations 10 times lower than earlier assays, extending its potential utility to monitoring cardiovascular risk in asymptomatic populations.1 Previous studies have demonstrated that a significant proportion of healthy middle-aged adults have detectable cardiac troponin T using a highly sensitive assay.2 The presence of detectable high-sensitivity cardiac troponin T (hs-cTnT) is believed to reflect subclinical myocardial damage and has been shown to strongly predict cardiovascular morbidity and mortality.3,4 Moreover, temporal decreases in hs-cTnT demonstrate a lower risk of cardiovascular events relative to patients with no significant change.4,5 Evidence suggests that hypertension, obesity, and diabetes are important risk factors for temporal changes in hs-cTnT.6,7 Because these clinical risk factors are influenced by **`lifestyle`**, the impact of health behaviors on temporal decreases in hs-cTnT is of substantial clinical interest. **Identifying modifiable lifestyle factors associated with temporal reductions in hs-cTnT has potential utility for `monitoring` the beneficial impacts of health behaviors on cardiovascular risk during the subclinical period.** The primary objective of our study was to investigate the associations between lifestyle-related health behaviors and 6-year decreases in hs-cTnT.\n\n---Identifying favorable lifestyle and other variables associated with temporal reductions in hs-troponin is increasingly relevant, as this assay tracks well with clinical risk.4,5 Several studies have now shown that temporal reductions in hs-troponin are associated with relative reductions in clinical events.4,5,16 This finding suggests the potential of hs-troponin to serve as a dynamic and individualized marker of CVD risk that may respond to preventive interventions.17 Changes in high-sensitivity troponin over time may be used in clinical practice as a marker of the impact of lifestyle modifications on cardiovascular health to counsel patients during the subclinical period. Moreover, subclinical markers may serve as tools to increase medication compliance and to motivate patients’ behavior change.18\n\n----Multifaceted lifestyle interventions that target several different health factors may have a greater impact on progression of subclinical cardiac disease than any single lifestyle factor alone.28 **As such, our results suggest that hs-cTnT may be a useful clinical tool for monitoring the effects of lifestyle interventions on cardiac health in the primary care setting.5** Other cardiac biomarkers have shown prognostic value in assessing future cardiovascular risk during the subclinical period as well,29 but further research is necessary to determine the association between these cardiac biomarkers and changes in lifestyle factors. \n\n----These data add to growing evidence that hs-cTnT may be a useful cardiovascular surrogate that is altered in response to lifestyle and behavioral risk factors"},{"_id":"4103ecc763376d0ba30000e7","treeId":"5fd161d2a87c2c03d5d940a9","seq":21963004,"position":1,"parentId":"41050238dd6f92fd2e0000e2","content":"* The effects of exercise on cardiovascular biomarkers in patients with chronic heart failure\n\n---- 我们的结果有临床意义\n---- We believe that these data have important clinical implications as biomarker-guided therapy becomes more routine in the management of chronic HF, and effects of key therapeutic interventions on serial biomarker levels require clarification. Although exercise training has a class 1 recommendation by both the 2012 European Society of Cardiology and 2013 American College of Cardiology/American Heart Association guidelines for the treatment of chronic HF, its effects on serial levels of commonly measured cardiovascular biomarkers are unclear.1,2 This study, an analysis of the definitive trial of exercise training in HF that led to the recommendations above, is the first to have standardized ascertainments of detailed exercise data and serial biomarker measurements on HF patients randomized to exercise interventions versus standard of care and found no meaningful effect of exercise on serial levels.\n\n----The most immediate clinical implications of our results relate to the use of exercise to reduce natriuretic peptide levels in patients with chronic HF, a strategy that has been perpetuated in the literature as accepted wisdom.1,5"},{"_id":"41649bae707f97bfc000008d","treeId":"5fd161d2a87c2c03d5d940a9","seq":21922935,"position":0.25,"parentId":"41c9f927305e62fb6e000045","content":"* Cardiac Troponin T in Healthy Full‑Term Infants\n\n---- 这个发现是重要的,因为...\n---- The broad range in hs-cTnT seen in our study indicates that even significantly elevated values during this time period might be considered normal. **These findings are important, since cTnT and hs-cTnT is used in** the NICU to investigate possible cardiac insults due to, e.g., asphyxia, and a misinterpretation of elevated values might result in unnecessary interventions.\n\n---- 使用cTn作为...应小心\n-----These findings underline the need of caution when using single hs-cTnT values as markers of cardiac damage in newborn infants, and even repeated sampling might be of limited use in the clinical setting since the change of hs-cTnT over time is still not fully understood."},{"_id":"413e8e030190423da20000ad","treeId":"5fd161d2a87c2c03d5d940a9","seq":21942062,"position":1,"parentId":"41649bae707f97bfc000008d","content":"*Evidence of direct cardiac damage following high-intensity exercise in chronic energy restriction\n\n--- 这个信息有何用?\n---A greater understanding would be vitally important, not only for those working with females competing in so called “lean sports”, but also for the general exercising population and matters relating to public health. If a deleterious link between energy deficit and high-intensity exercise was identified, individuals who may be “at risk” could be identified from the risk stratification model proposed in Fig. 2. Subsequently, the most appropriate intervention for the individual could be initiated. \n--- As such the use of cutoff thresholds for normal healthy populations may need to be reconsidered in lean and energy deficient populations, particularly for use in long-term risk stratification."},{"_id":"412f48d13be8fa3e840000ba","treeId":"5fd161d2a87c2c03d5d940a9","seq":21950087,"position":1,"parentId":"413e8e030190423da20000ad","content":"* Association of novel biomarkers of cardiovascular stress with left ventricular hypertrophy and dysfunction: implications for screening\n\n--- 为何研究混杂因素,为何LVH要观察\n--- The more specific cardiac troponins were introduced later and are increasingly used. Peak and AUC of total CK and cTnI have been shown to correlate well with IS measured by goldstandard techniques. Owing to their cardiac specificity, troponins have become the reference biomarker for estimating IS and thus for predicting long-term clinical outcomes after STEMI,4,24 and, consequently, many experimental studies and clinical trials use cardiac troponins as the primary outcome measure.8,25,26 It is therefore important to identify confounders that affect the release and quantification of cardiac troponins. Given the high prevalence of LVH in the general population (20% to 25%),11,12 and especially in the MI population (50%),27 it is of great importance to know whether LV mass affects the systemic release of biomarkers after an AMI."},{"_id":"4172d847a1d69f48ed00007d","treeId":"5fd161d2a87c2c03d5d940a9","seq":21950140,"position":0.5,"parentId":"41c9f927305e62fb6e000045","content":"* High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population\n\n--- **危险性标志物 重要的 具备条件 特征**\n---Two additional key requirements for a biomarker in the setting of CV risk screening is to be **responsive to modifications** of the CV risk and **to interventions** that effectively modify this risk, such as statins.\n---In a randomized study involving 307 elderly individuals (aged 70 or older), the adoption of a moderate level of physical activity attenuated the increase in hs-cTnT induced by aging at 12 months, in comparison with a sedentary lifestyle.51\n\n----**指导生活方式的干预**\n---**`The guidance of lifestyle intervention `**may be another potential application if the response of hs-cTn is confirmed by further trials."},{"_id":"4172c2eea1d69f48ed00007e","treeId":"5fd161d2a87c2c03d5d940a9","seq":21915501,"position":1,"parentId":"4172d847a1d69f48ed00007d","content":"* High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population\n\n--- 高敏测试:cTn出现在无症状的人群,危险分层、一次测试\n---The current commercially available hs-cTn assays provide cTn detection in a significant proportion of asymptomatic individuals, thus allowing its consideration for CV risk stratification in the general population **based on a single measurement**. Risk stratification in asymptomatic population concerns the range of cTn values between the lower limit of detection and the 99th percentile of normal and not higher values that are indicative of disease.31"},{"_id":"4172868ba1d69f48ed000080","treeId":"5fd161d2a87c2c03d5d940a9","seq":21915502,"position":1,"parentId":"4172c2eea1d69f48ed00007e","content":"* High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population\n\n--- cTn危险分层的目标人群:年轻人 获益大\n---Given the fact that management strategies at the two ends of the CV risk spectrum are rather clear, it could be argued that **`young `**to middle-aged individuals with low-moderate CV risk, according to existing screening tools, may benefit more from additional stratification tools. In the case of ESC-SCORE, this population corresponds to individuals with an estimated 10-year risk of fatal CV disease of 1–5%.19 This low-moderate 10-year risk may be translated into a high lifetime risk. Targeting these individuals with appropriate preventive interventions along with closer follow-up could prevent their progression to a higher risk group.18"},{"_id":"4172ba2fa1d69f48ed00007f","treeId":"5fd161d2a87c2c03d5d940a9","seq":21915476,"position":2,"parentId":"4172d847a1d69f48ed00007d","content":"* High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population\n\n--- cTn 是个有价值的危险分层的指标\n---The accumulated bulk of evidence shows that hs-cTn predicts future CV events, including mortality, MI, and HF (Table 4). At the same time, the biomarker is **responsive to preventive interventions** such as statin therapy, weight control or increased physical activity, while its values parallel CV risk modification. In addition, the use of hs-cTn in this setting improves risk prediction when added to well-established prognosticators, a fact that may be partly related to its cardiac specificity. The incremental prognostic value of hs-cTn may help addressing the residual CV risk not covered by established prognostic markers and tools. Evidence shows that this approach may further be cost-effective.52"},{"_id":"41c35574836b50d2f600004c","treeId":"5fd161d2a87c2c03d5d940a9","seq":21897227,"position":1,"parentId":"41c9f927305e62fb6e000045","content":"### 运动 生活方式 好处\n* early evaluation of myocardial injury by means of high-sensitivity methods for cardiac troponins after strenuous and prolonged exexrcise\n\n---It is **unanimously accepted** that regular physical exercise is part of a healthy **lifestyle**.1, 2 indeed, a plethora of experimental and clinical studies have **definitively demonstrated** that regular physical activity is associated with reduced cardiovascular risk and mortality rate for cardiac disease.1-3 in particular, a lot of evidence from large population-based, prospective observational studies has shown that maintaining or improving fitness is associated with lower cardiovascular disease risk; on the contrary, low cardiorespiratory fitness is associated to increased risk for myocardial dysfunction and morality cardiac rate.1-3"},{"_id":"41c318a504a531594e00004d","treeId":"5fd161d2a87c2c03d5d940a9","seq":21915146,"position":2,"parentId":"41c9f927305e62fb6e000045","content":"### 微小增加即有意义\n* early evaluation of myocardial injury by means of high-sensitivity methods for cardiac troponins after strenuous and prolonged ex\n\n---These data are well in accordance with some recent results reporting that even small, but progressive increments of hs-cTni values (such as about 5 ng/L) can significantly increase the cardiovascular risk **in asymptomatic individuals in a general population**.\n\n29.Association of repeatedly measured high-sensitivity-assayed troponin i with cardiovascular disease events in a general population from the MorGaM/Biomarcare Study. clin chem 2017\n\n* High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population\n\n--- 微小的升高有意义\n---More recent evidence confirms that even minimal elevations of hs-cTn concentration within the normal range, i.e. below the 99th percentile of normal, may predict CV disease and mortality in the asymptomatic individuals."},{"_id":"415b16ad507e3246ef000097","treeId":"5fd161d2a87c2c03d5d940a9","seq":21927720,"position":1,"parentId":"41c318a504a531594e00004d","content":"* Prevalence and determinants of troponin T elevation in the general population\n\n---**微小的升高**\n---Cardiac troponins are increasingly being measured in patients without typical symptoms of ischemic chest pain, and physicians struggle to interpret troponin elevation in these settings, e**specially when levels are only minimally elevated**. In part, this difficulty arises because little is known about the frequency and clinical correlates of troponin elevation in the ambulatory setting. We measured cardiac troponin T (cTnT) in a large population sample from Dallas, Tex, and identified that 0.7% of adult subjects had an elevated cTnT (\u00010.01 g/L). cTnT elevation was associated with a high-risk cardiovascular profile, even when levels were **`only minimally elevated`** (0.01 to 0.03 g/L)."},{"_id":"41b2e0cc9d055c7daf000056","treeId":"5fd161d2a87c2c03d5d940a9","seq":21892254,"position":2.5,"parentId":"41c9f927305e62fb6e000045","content":"### 规律运动的人不应纳入cTn范围研究\n* How is cardiac troponin released from injured myocardium?\n----In addition, as indicated above, normal subjects and even healthy athletes show cTn increases in association with heavy endurance exercise. **Individuals performing such heavy physical activities regularly, therefore, `should not be included` in future cTn normal range studies for cTn assays with high analytical sensitivity.** As a further example, consider an individual with hypertension and left ventricular hypertrophy who has a baseline value"},{"_id":"415476a265ab5d79ac0000a3","treeId":"5fd161d2a87c2c03d5d940a9","seq":21930220,"position":1,"parentId":"41b2e0cc9d055c7daf000056","content":"* Cardiac troponin I is released following high-intensity short-duration exercise in healthy humans\n\n---- 习惯规律运动者可能会使安静态cTn增加,干扰危险分层,特别是在高危人群\n---- Accordingly, it is highly likely that a large percentage of the population regularly engage in exercise that will stimulate a physiological release of cTn. Whilst not problematic in the healthy population, an exercise associated release of cTn may become diagnostically important if an individual is admitted to hospital with the suspected acute coronary syndrome. The current drive for highly sensitive cTn assays [6] will likely lead to increased detection of exercise-associated increases in cTn. Moreover, the very low background concentrations of cTn shown in the normal healthy population [7] may also result in cTn positive samples using highly sensitive assays. Accordingly, before the wholesale adoption of highly sensitive assays occurs it is important that appropriate clinical guidelines are established that consider both normal circulating levels and exercise associated elevations in cTn."},{"_id":"4132b73f7eeb97844d0000b7","treeId":"5fd161d2a87c2c03d5d940a9","seq":21947443,"position":1,"parentId":"415476a265ab5d79ac0000a3","content":"* Association of Novel Biomarkers of Cardiovascular Stress With Left Ventricular Hypertrophy and Dysfunction: Implications for Screening\n\n---- 当运动训练时,作为普查指标将**面临挑战**, 仍需大样本的实验验证我们的结果\n----However, the clinical significance of the modest NRI values remains unclear, thereby **rendering it challenging to advocate the use of these novel biomarkers for screening purposes** in clinical practice. Additional studies of larger multi-ethnic cohorts are warranted to confirm our results and further investigations are needed to elucidate the clinical significance of modest NRI values (which may be statistically significant)."},{"_id":"41b2efc69d055c7daf000055","treeId":"5fd161d2a87c2c03d5d940a9","seq":21892244,"position":3,"parentId":"41c9f927305e62fb6e000045","content":"### 安静值:危险分层也有价值\n* How is cardiac troponin released from injured myocardium?\n----As a further example, consider an individual with hypertension and left ventricular hypertrophy who has a baseline value for hs-cTn near the upper reference limit (URL). His postoperative cTn values could easily exceed the URL with a small to modest increase in response to volume expansion and/or catecholamine treatment, which could be consistent with a normal response. If this is true, we should not consider such increases to be clinically relevant. Indeed, in this example suggested, it may be that the **`cTn baseline concentrations are more relevant for risk stratification`** similar to exercise stress testing in patients with stable CAD.13\n"},{"_id":"41a3208f82f21f5e8a000065","treeId":"5fd161d2a87c2c03d5d940a9","seq":21897878,"position":4,"parentId":"41c9f927305e62fb6e000045","content":"* High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014\n\n---- 训练,是个干扰因素\n----Use of smokeless tobacco is associated with lower circulating cardiac troponin concentrations both in the resting state and after exercise, and tobacco use should be taken into account when interpreting cardiac troponin test results.\n----训练,干扰了cTn与心血管健康的关系\n----Although the clinical applicability of the results is unknown, it signals that smokeless tobacco use may confound the association between cTn and cardiovascular health."},{"_id":"418fb9c3414babe26100007b","treeId":"5fd161d2a87c2c03d5d940a9","seq":21903579,"position":1,"parentId":"41a3208f82f21f5e8a000065","content":"当人们已知到cTn检测前应避免剧烈运动时,我们的研究进一步增加了知识:处于训练期间的人即便休息了48小时,仍可影响cTn的检测。"},{"_id":"418f90f6414babe26100007c","treeId":"5fd161d2a87c2c03d5d940a9","seq":21915343,"position":1,"parentId":"418fb9c3414babe26100007b","content":"* High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population\n\n--- **排除运动的干扰**\n---The concentration of hs-cTn can further be increased by physical exercise or extra-cardiac conditions. `Simple measures to address these issues `could be to avoid hs-cTn testing after exercise or during disease, to confirm levels by repeated measurements and to assess longitudinal changes.?"},{"_id":"4159a026486e3540a800009c","treeId":"5fd161d2a87c2c03d5d940a9","seq":21928687,"position":0.5,"parentId":"418f90f6414babe26100007c","content":"* Predictors of cardiac troponin release after a marathon\n\n--- 解释cTn应谨慎\n--- We found that 96% of our marathon athletes demonstrated an increase in cTnI, while 69% of our population exceeded the clinical cut-off value. Since cTnI is recommended as a sensitive and specific marker for cardiac damage in the diagnosis of acute myocardial infarction,3,32 `caution should be taken when interpreting` postrace cTnI levels. As our participants did not report any symptoms, it is likely that the elevated cTnI levels represent a physiological rather than a pathological response.33 Clinicians should therefore take caution when examining troponin levels without clinical signs indicative of myocardial ischaemia.34 Our study provides some additional clinical insight as we found that lower age and longer exercise duration, albeit weakly, independent predict post-race cTnI levels. Such information is relevant for clinicians as it could improve medical decision making."},{"_id":"415b1c4c507e3246ef000096","treeId":"5fd161d2a87c2c03d5d940a9","seq":21927717,"position":1,"parentId":"418f90f6414babe26100007c","content":"* Prevalence and determinants of troponin T elevation in the general population\n\n---临床医生`应该意识`到:是。。不是急性心梗\n---Practicing **physicians should realize** that cTnT elevation is extremely rare among healthy subjects but is relatively common in the presence of cardiac structural and functional abnormalities, diabetes, or renal insufficiency. For example, in the patient with diabetes, moderate renal insufficiency, and left ventricular hypertrophy who presents to the emergency department with atypical chest pain symptoms, minimal troponin elevation may reflect the influence of underlying chronic disease and **`not be indicative of`** an acute coronary syndrome event."},{"_id":"416df125057828bcfc000085","treeId":"5fd161d2a87c2c03d5d940a9","seq":21917277,"position":2,"parentId":"418fb9c3414babe26100007b","content":"* Physical activity - an important preanalytical variable\n\n--- 运动 训练,影响 化验结果的误解;戒除运动48小时\n--- It is hence noteworthy that test results that fall outside the conventional reference ranges in athletes not only may reflect the presence of a given disease, but may frequently **mirror an adaptation to regular training** or changes that have occurred during and/or **following strenuous exercise**, and which should be clearly acknowledged to prevent misinterpretation of laboratory data. \n--- Accordingly, the values of some biomarkers in physically active subjects should be cautiously interpreted, since their results may fall outside the conventional reference ranges, reflecting an adaptation to regular training or changes that have occurred during and/or following strenuous exercise, **rather than the presence of a given disease**.\n\n- Patients with certain elevated or decreased analytes and uncertain findings should therefore be asked whether they had been physically active around the time when the test was taken or maybe regularly physical active. Alternatively, the abstention from physical exercise **`48 h`** before blood sampling should be considered."},{"_id":"412ed60e3be8fa3e840000bd","treeId":"5fd161d2a87c2c03d5d940a9","seq":21950142,"position":4.5,"parentId":"41c9f927305e62fb6e000045","content":"* Association of novel biomarkers of cardiovascular stress with left ventricular hypertrophy and dysfunction: implications for screening\n\n---- **此结果并未否认cTn的诊断价值**,而是提示LVmass作为一个混杂因素/无关变量,这特别重要的在...情况下\n----The influence of LVH on cTnI release after myocardial damage reported here **`does not invalidate the use of troponins as surrogate`** markers, but shows **the need to take LV mass into account as an important potential confounding factor** in clinical and research evaluations. These considerations could be **especially important in **determining the significance of small increases in circulating troponin in patients presenting to the emergency department, given that troponin readings in patients with LVH may give a false-positive diagnosis of MI.36 In this regard, mild increases in troponin-I37–40 or troponin-T41 have been reported in patients with LVH in the absence of chest pain or any other acute condition. In addition, it has been recently reported that cardiac troponin concentrations correlate with LV mass index independent of coronary artery disease status in patients with aortic valve stenosis.42,43 Presence of a dynamic pattern (rise and/or fall) in cardiac troponin values along with clinical evidence of ischemia can be of help to confirm the diagnosis of MI in these contexts. Although the aims of our study were beyond these important issues, our data support that, for a given small stress to the myocardium, troponin release in patients with LVH might be larger than in patients with normal LV mass."},{"_id":"419bcb99e7d3819fe200006b","treeId":"5fd161d2a87c2c03d5d940a9","seq":21899923,"position":5,"parentId":"41c9f927305e62fb6e000045","content":"### 提示未来的研究方向"},{"_id":"419bca9fe7d3819fe200006c","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954287,"position":1,"parentId":"419bcb99e7d3819fe200006b","content":"* High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014\n\n----提示未来的研究\n----The current results, combined with data from prior reports observing an inverse association between cigarette smoking and concentrations of cTn, suggest that the effect is real and **underscore the need for further experimental research exploring the potential underlying mechanisms for this apparently paradoxical phenomenon.**"},{"_id":"416ee4ba1fdc97a30f000082","treeId":"5fd161d2a87c2c03d5d940a9","seq":21916990,"position":2,"parentId":"419bcb99e7d3819fe200006b","content":"* High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population\n\n--- 机制并未完全理解;解决机制有助于确定预防干预的新靶点。\n--- The predominate trigger and exact mechanisms of cTnT/I release from cardiomyocytes in asymptomatic individuals **are incompletely understood**.58 Elucidation of the underlying pathophysiology by studies addressing sensitive indices of CV function, besides improving our understanding, may further contribute to the identification of **novel targets **for preventive interventions. "},{"_id":"416eccb71fdc97a30f000085","treeId":"5fd161d2a87c2c03d5d940a9","seq":21917015,"position":3,"parentId":"419bcb99e7d3819fe200006b","content":"* High-sensitivity cardiac troponin assays for cardiovascular risk stratification in the general population\n\n--- 今后的工作,谁应该、5隔多久、用什么干预措施?\n--- Several issues described above need to be addressed by prospective randomized studies that would **`translate` the important prognostic features of hs-cTn into a comprehensive strategy**, defining **who should be screened, how often should monitoring occur, and what should be the interventions** in people with increased risk. The education of the wide spectrum of physicians involved in primary prevention, including cardiologists, general practitioners, family doctors, internists, and other specialists, is required to raise awareness of this novel feature of hs-cTn and facilitate its future clinical endorsement."},{"_id":"4138c51aa80a3e0c870000b5","treeId":"5fd161d2a87c2c03d5d940a9","seq":21945630,"position":4,"parentId":"419bcb99e7d3819fe200006b","content":"* High-sensitivity cardiac troponin T in young, healthy adults undergoing non-cardiac surgery\n\n--- 需解决。。\n--- Thus, additional research is needed to determine how much change in hscTnT can be expected after operation as part of normal physiology vs a truly pathological process. This is of particular importance given the modest changes we observed in our putatively normal patients, with most hscTnT increases at <4 ng litre\u00031. "},{"_id":"410855d0662ffba61d0000e1","treeId":"5fd161d2a87c2c03d5d940a9","seq":21962127,"position":1,"parentId":"4138c51aa80a3e0c870000b5","content":"* Mental Stress, Exercise, and Other Determinants of Elevation in High-Sensitivity Troponin Levels: A Call for Standardization of Laboratory Protocols\n\n---- 众多的影响安静cTn的因素,增加了复杂性。测试标准化\n----**There is a growing understanding of the multifactorial determinants of hs-cTnI elevations.** As Hammadah et al. (14) point out, these determinants include factors such as heart failure, myocarditis, pulmonary embolism, sepsis, and hypertensive crisis. In addition, various cardiac factors appear to increase the risk for observing elevations in hs-cTnI elevations in CAD populations, including reduced left ventricular ejection fraction, resting perfusion defects, reduced exercise capacity, left atrial size, and diastolic function (2,11,17). The multifactorial determinants of troponin elevations **adds complexity to** the present study due to the heterogenous nature of the study cohort. Among the patients, 31% had a history of prior myocardial infarction and 13% had a history of heart failure. The presence of resting wall motion abnormality, itself, manifested a moderate correlation with hs-cTnI levels in this study, comparable to that noted between ischemia and hs-cTnI levels. As Hammadah et al. (14) noted, resting perfusion defects and inducible ischemia appeared to be synergistic predictors of hs-cTnI elevations.\n\n---Hammadah et al. (14) have performed a large-scale study that confirms and extends the results of prior studies that have demonstrated that elevations in resting hs-troponin levels identify patients who are more prone to stress-induced ischemia, during both exercise and mental stress. Conversely, patients with inducible ischemia have higher resting hs-troponin levels. These and other observations further an emerging consensus that elevations of hs-troponin exists along a continuum of precipitants, ranging from the presence and magnitude of a coronary atherosclerotic burden to the induction of ischemia, development of acute coronary syndromes, and occurrence of myocardial infarction. Because the pathophysiological determinants of cTn levels are multifactorial, there is a need to standardize the methods for conducting laboratory investigations into the precipitants and measurements of troponin elevations during exercise- and mental stress testing. Such standardization could lead to an enhanced ability to compare the results emanating from different medical centers and to study causal mechanisms.\n"},{"_id":"41c9f876305e62fb6e000046","treeId":"5fd161d2a87c2c03d5d940a9","seq":21886901,"position":6,"parentId":"41d01a6b6b30a8b7c200011c","content":"## Limitations\nWhen best to assess resting levels and what other factors mediate resting levels"},{"_id":"41c48c20836b50d2f6000049","treeId":"5fd161d2a87c2c03d5d940a9","seq":21897485,"position":1,"parentId":"41c9f876305e62fb6e000046","content":"### 寻找最佳测试点或窗口\n"},{"_id":"4164a6d7707f97bfc000008c","treeId":"5fd161d2a87c2c03d5d940a9","seq":21922898,"position":0.25,"parentId":"41c48c20836b50d2f6000049","content":"* Cardiac Troponin T in Healthy Full‑Term Infants\n\n---- 仍需解决:时间点\n---- It is not clarified at what time point cTnT reaches its highest levels postnatally nor when it equals adult reference values.\n---- **Further studies are warranted to clarify at what time point** hs-cTnT reaches its highest levels after birth and when it equals normal adult values."},{"_id":"41647df0707f97bfc000008e","treeId":"5fd161d2a87c2c03d5d940a9","seq":21923616,"position":1,"parentId":"4164a6d7707f97bfc000008c","content":"* Cardiac Troponin T in Healthy Full‑Term Infants\n\n---- 只测量了2次cTn, 在小的窗口\n---- The main limitation of this study was that we only measured hs-cTnT **at two occasions and within a rather narrow time span**. We were able to show a significant increase in hs-cTnT values during the first days of life, but we still do not know **when hs-cTnT reaches its highest levels after birth or at what time point it descends to normal adult values**. Furthermore, due to a limited number of infants it was not feasible to investigate whether there was a significant difference in hs-cTnT values between infants born after vaginal delivery and those born after acute CS or vacuum extraction."},{"_id":"4162eeb87010b48d1300008f","treeId":"5fd161d2a87c2c03d5d940a9","seq":21926234,"position":1,"parentId":"41647df0707f97bfc000008e","content":"----应多点测量;观察点\nIn addition to the potential mechanisms described in our paper, it is possible that exercise-induced myocyte turnover influenced conduction pathways. However, **we did not take measurements at `multiple time points` to determine the time course of these outcome measures** in response to challenging exercise. **Further work is required to elucidate** the mechanisms and significance of exercise-induced arrhythmias."},{"_id":"413e91900190423da20000ac","treeId":"5fd161d2a87c2c03d5d940a9","seq":21942051,"position":1,"parentId":"4162eeb87010b48d1300008f","content":"*Evidence of direct cardiac damage following highintensity exercise in chronic energy restriction\n\n--- 得知影响因素以及何时测试能显示出适应的效应,有何价值\n---**`This information may also assist with clinical interpretations and judgments when conducting risk stratification of individuals presenting with raised cTn levels in the absence of other clinical evidence of acute coronary syndrome.`**"},{"_id":"41a4663682f21f5e8a00005c","treeId":"5fd161d2a87c2c03d5d940a9","seq":21897436,"position":0.5,"parentId":"41c48c20836b50d2f6000049","content":"* Relationship between Post-Exercise Plasma CK Elevation and Muscle Mass Involved in the Exercise\n\n---- If a study is carefully designed to **eliminate an adaptation effect** and an eccentric exercise that has been reported to produce substantial muscle damage is used for an exercise model, a relationship between the amount of increase in CK and damage size **may be possible to find**."},{"_id":"41b385559d055c7daf000054","treeId":"5fd161d2a87c2c03d5d940a9","seq":21897484,"position":1,"parentId":"41c48c20836b50d2f6000049","content":"* How is cardiac troponin released from injured myocardium? \n---**A limitation of** these experiments was that apoptosis was claimed **instead of being based on** electron microscopy morphological findings **only on the basis of** standard biochemical methods (i.e. terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling – positive nuclei and immunostaining for active caspase-3), which have also **been criticized for lack of **sensitivity and specificity for apoptosis.2 Therefore, to** `overcome this`** the diagnosis of ‘apoptotic cardiomyocytes’ required that cardiomyocytes stained positive with both biochemical methods. **`Ideally`**, however, a morphological workup of the hearts using electron microscopy **would have been necessary to undoubtedly **prove cardiomyocyte apoptosis and the absence of cardiomyocyte necrosis.2 But this is **obviously very labor-intensive** and difficult to perform in such kinds of experiments."},{"_id":"41a4644e82f21f5e8a00005d","treeId":"5fd161d2a87c2c03d5d940a9","seq":21897438,"position":1.5,"parentId":"41c9f876305e62fb6e000046","content":"### 安静值另外的影响因素"},{"_id":"41a40da882f21f5e8a00005e","treeId":"5fd161d2a87c2c03d5d940a9","seq":21897491,"position":1,"parentId":"41a4644e82f21f5e8a00005d","content":"* How is cardiac troponin released from injured myocardium? \n---The extent to which these alternative mechanisms of cTn release contribute to small hs-cTn elevations which are seen in daily clinical practice still remains to be shown more definitively, but this should be an area of further future investigation.\n这些cTn释放的替代机制在多大程度上导致了小的hs-cTn升高(在日常临床实践中可见)仍有待进一步证实,但这应该是未来进一步研究的一个领域。"},{"_id":"419ca321e7d3819fe2000067","treeId":"5fd161d2a87c2c03d5d940a9","seq":21899800,"position":2,"parentId":"41a4644e82f21f5e8a00005d","content":"* High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014\n\n----概述运动性cTn及意义挑战\n----**提示进一步工作**\n----**`An increase in concentrations of cTn following intense exercise is commonly observed`**.2 Activity-related changes in serum enzymes have been known for several decades,18,19 and, in line with these observations, exercise-induced troponin increase has traditionally been considered a benign and physiological phenomenon. However, recent observations demonstrating associations between the magnitude of postexercise troponin response and cardiovascular disease and outcome20,21 challenge this concept. Moreover, **`it highlights that more detailed information is needed on determinants`** of the magnitude of transient elevations of cTn following exercise. "},{"_id":"41be7485482816e167000052","treeId":"5fd161d2a87c2c03d5d940a9","seq":21886905,"position":2,"parentId":"41c9f876305e62fb6e000046","content":"### 更长的训练期\n* Measurement of circulating concentrations of cardiac troponin I and T in healthy subjects: a tool for monitoring myocardial tissue renewal?\n ---In conclusion, some recent findings (33, 38–43) may explain why plasma troponin concentrations are increased in the absence of myocardial necrosis in some pathological conditions. However, `we cannot exclude other` mechanisms, independent of myocardial necrosis and integrin-mediated myocardial stretch that might be involved in the degradation and release of troponins from myocardial cells. `Further studies are necessary to accurately describe` the cellular mechanisms responsible for the release of cTnI and cTnT from damaged and/or viable cardiomyocytes."},{"_id":"419be5f1e7d3819fe200006a","treeId":"5fd161d2a87c2c03d5d940a9","seq":21899907,"position":3,"parentId":"41c9f876305e62fb6e000046","content":"* High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014\n\n**----不能外推至另外的人群**\n----Third, our study includes a White cohort and the sample mainly included snus-using men. The findings may not be generalizable to individuals of other ethnic groups or to women. "},{"_id":"419840ad6de926ef30000074","treeId":"5fd161d2a87c2c03d5d940a9","seq":21900391,"position":1,"parentId":"419be5f1e7d3819fe200006a","content":"Second, we acknowledge the potential for limited generalizability. We studied young, healthy rowers, and thus our results may not generalizable to athletes participating in other forms of ET or patients with cardiovascular diseases."},{"_id":"41984aa66de926ef30000073","treeId":"5fd161d2a87c2c03d5d940a9","seq":21900389,"position":4,"parentId":"41c9f876305e62fb6e000046","content":"### 样本量小\n---- First, we acknowledge that our sample size was relatively small. However, our use of a longitudinal, repeated measures study design in which each individual acted as his own control maximized our ability to define causal relationships between ET and NP release.In addition, the use of a prior power calculations coupled with the directional consistency of our pre- and post-echocardiographic data (Fig. 1) provides reassurance that we were amply powered to capture meaningful physiologic change and that our aggregate results are not driven by outliers (type 1 error)."},{"_id":"41983e2b6de926ef30000075","treeId":"5fd161d2a87c2c03d5d940a9","seq":21900392,"position":5,"parentId":"41c9f876305e62fb6e000046","content":"### 超声测试 不如 MRI\n----Third, we acknowledge that echocardiography may produce relatively inaccurate absolute estimates of LV mass compared with cardiac magnetic resonance imaging. However, our favorable intraobserver variability data, explained by the use of a single trained sonographer and a single experienced interpreter of echocardiographic data, emphasize the accuracy of the observed changes in LV mass between the two study time points."},{"_id":"41983ac96de926ef30000076","treeId":"5fd161d2a87c2c03d5d940a9","seq":21900407,"position":6,"parentId":"41c9f876305e62fb6e000046","content":"### 其他心腔\n* Endurance exercise training attenuates natriuretic peptide release during maximal effort exercise: biochemical correlates of the “athlete’s heart\n\n---- 其他心腔的影响\n---- Finally, we are unable to comment on the relative contributions of individual cardiac chambers to levels of postexercise plasma NP levels. Future work will be required to clarify whether both right- and left-sided atria and ventricles contribute similarly to this phenomenon."},{"_id":"41169ca9c90d6987c60000da","treeId":"5fd161d2a87c2c03d5d940a9","seq":21959385,"position":1,"parentId":"41983ac96de926ef30000076","content":"* Exercise-Induced Cardiac Remodeling Not a Case of One Size Fits All\n\n----Second, EICR changes of the **right ventricle** were not addressed in this study. In comparison to the left ventricle, the right ventricle suffers a disproportionately high afterload during intense exercise because of the relative pressure increase in the pulmonary circulation exceeding that of the systemic circulation.20 In this regard, one might expect the right ventricle to be the seat of the most profound EICR changes and, therefore, should not be neglected. Arbab-Zadeh et al11 demonstrated that with increasing exercise load, there was eccentric hypertrophy of the right ventricle with a relatively constant right ventricular mass to volume ratio throughout training."},{"_id":"4104fa0cdd6f92fd2e0000e5","treeId":"5fd161d2a87c2c03d5d940a9","seq":21962953,"position":7,"parentId":"41c9f876305e62fb6e000046","content":"* Relation of Lifestyle Factors and Life’s Simple 7 Score to Temporal Reduction in Troponin Levels Measured by a High-Sensitivity Assay (from the Atherosclerosis Risk in Communities Study)\n\n---只有两个观察点\n----First, hs-cTnT was measured at only 2 time points; thus, we were unable to evaluate more granular trends in subclinical myocardial damage with various lifestyle factors"},{"_id":"4103a248e080de4b060000ed","treeId":"5fd161d2a87c2c03d5d940a9","seq":21963091,"position":8,"parentId":"41c9f876305e62fb6e000046","content":"* The effects of exercise on cardiovascular biomarkers in patients with chronic heart failure\n\n\n----研究限制\n----There are potential limitations to the present study. The population for this study was derived from the HFACTION trial and is susceptible to the limitations inherent in clinical trial populations. Biomarker measurements were made after 3 months of structured exercise training, and there is a possibility that changes in levels might have been noted after a longer exercise period. Our study population consisted only of patients with impaired ejection fraction (LVEF b35%), so our results cannot be extrapolated to the population of patients with HF and preserved ejection fraction. Our population consisted of ambulatory patients with NYHA class II and III HF, and these findings may not be generalizable to patients with less or more severe illness. We used a commonly used platform for measurement of cTnT, rather than the newer high sensitivity assays used in more recent studies of troponin elevation in HF.30"},{"_id":"40fe28220e891323a00000f7","treeId":"5fd161d2a87c2c03d5d940a9","seq":21964561,"position":9,"parentId":"41c9f876305e62fb6e000046","content":"* Impact of moderate physical activity on the longitudinal trajectory of a cardiac specific biomarker of injury: Results from a randomized pilot study of exercise intervention\n\n----研究限制\n----This study, by design, was intended as a feasibility pilot study to determine if older sedentary adults could be successfully randomized to a physical activity intervention and determine if this resulted in differences in physical performance. It was not designed to detect differences in clinical outcomes between the 2 groups, and a prior report of the LIFE-P results shows that there was not a significant difference in time to major mobility disability or death.13\n\n---Another limitation is that not all enrolled subjects had baseline and 1-year blood samples available for measurement, which could potentially have biased our results. In the absence of information on clinical outcomes, we were unable to determine whether these small but significant differences in longitudinal progression of hs-cTnT levels are clinically meaningful.- \n\n---Furthermore, the intensity of the physical activity intervention arm was moderate, as suggested by the achieved physical activity of 135minutes per week in this group, lower than the consensus guideline recommendation of 150minutes weekly.16\n"},{"_id":"4160eaaeffcb296715000093","treeId":"5fd161d2a87c2c03d5d940a9","seq":21926581,"position":7,"parentId":"41d01a6b6b30a8b7c200011c","content":"## Conclusion"},{"_id":"4160e957ffcb296715000094","treeId":"5fd161d2a87c2c03d5d940a9","seq":21926582,"position":1,"parentId":"4160eaaeffcb296715000093","content":"This has important implications, particularly **when assessing patients with** possible ACS in the Emergency Department."},{"_id":"412500ec71622f36800000ca","treeId":"5fd161d2a87c2c03d5d940a9","seq":21954558,"position":2,"parentId":"4160eaaeffcb296715000093","content":"* High-Intensity Interval Training Improves Left Ventricular Contractile Function\n\n----描述主要发现\n---- Typically, the exercise training effect on cardiac function is assessed by M-mode in echocardiography, which only displays the size of ventricular cavity, myocardial thickness, the integrity of interventricular septum, and the motion of ventricular wall at rest (8). The present study further contributes to a greater understanding of LV mechanical responses to various exercise regimens using stress echocardiography. In summary, HIIT for 6 wk induces eccentric myocardial hypertrophy, enhances myocardial performance, and reduces peak torsion to reduce energy consumption for myocardial contraction, thereby improving LV contractile function. On the other hand, this exercise regimen also improves diastolic function by increasing the Vp and the E/A ratio as well as reducing the time to reach peak untwisting velocity, consequently increasing SV. **Although MICT modestly elevates myocardial contractility, cardiac diastolic function `remains unchanged after this exercise intervention`.** The present findings provide a new insight into the superior effects of HIIT on LV mechanics during exercise by simultaneously increasing contractile and diastolic functions and may have important implications for exercise training in cardiac rehabilitation."},{"_id":"5fd161d2a87c2c03d5d940aa","treeId":"5fd161d2a87c2c03d5d940a9","seq":21877074,"position":1,"parentId":null,"content":"# Title: **Statement** of your core result or finding.\nTry to make your title an assertive statement, such as:\n- \"Changes in cytoplasmic volume are sufficient to drive spindle scaling.\" \n\nand not\n- \"High-performance silicon photoanodes passivated with ultrathin nickel films for water oxidation\"\n\nRule of thumb: if your title would look weird with a period at the end, it is probably a poor title.\n\nDon't do [this](http://www.phdcomics.com/comics/archive/phd053106s.gif)."}],"tree":{"_id":"5fd161d2a87c2c03d5d940a9","name":"cTnT&LVmass","publicUrl":"c-tn-t-l-vmass","latex":true}}