Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK.
Scand J Med Sci Sports. 2013 Mar;23(2):224-31. doi: 10.1111/j.1600-0838.2011.01376.x. Epub 2011 Sep 13.
Cardiac electrical-mechanical delay (cEMD), left ventricular (LV) function, and cardiac troponin I (cTnI) were assessed after 40 km cycle time trials completed at high (HIGH) and moderate (MOD) intensities in 12 cyclists. Echocardiograms and blood samples were collected before, 10, and 60 min after cycling. cEMD as assessed by time from QRS onset to peak systolic (S') tissue velocity was lengthened after both bouts of cycling but was not mediated by cycling intensity (HIGH: 174 ± 52 vs 198 ± 26 ms; MOD: 151 ± 40 vs 178 ± 52 ms, P < 0.05). Global LV systolic function was unaltered by exercise. cEMD from QRS to peak early (E') diastolic tissue velocity was also increased post-exercise (HIGH: 524 ± 95 vs 664 ± 68 ms; MOD: 495 ± 62 vs 604 ± 91 ms, P < 0.05). Indices of LV diastolic function was reduced after cycling but were not mediated by exercise intensity. cTnI was elevated in two participants after HIGH trial (0.06 ug/L; 0.04 ug/L) and one participant after MOD trial (0.02 ug/L). While cEMD is lengthened and LV diastolic function was reduced post-cycling, altering time-trial intensity had little impact upon cEMD, LV function, and cTnI release.
在 12 名自行车运动员中，分别在高强度（HIGH）和中强度（MOD）下完成 40 公里计时赛后，评估了心脏电机械延迟（cEMD）、左心室（LV）功能和心脏肌钙蛋白 I（cTnI）。在运动前、运动后 10 分钟和 60 分钟采集了超声心动图和血液样本。通过从 QRS 起点到收缩期（S'）组织速度峰值的时间评估 cEMD，两种运动后均延长，但不受运动强度的影响（HIGH：174±52 对 198±26 ms；MOD：151±40 对 178±52 ms，P<0.05）。运动后整体 LV 收缩功能未发生变化。从 QRS 到舒张早期（E'）组织速度峰值的 cEMD 也在运动后增加（HIGH：524±95 对 664±68 ms；MOD：495±62 对 604±91 ms，P<0.05）。LV 舒张功能的指标在运动后降低，但不受运动强度的影响。HIGH 试验后有两名参与者（0.06 ug/L；0.04 ug/L）和一名参与者在 MOD 试验后（0.02 ug/L）的 cTnI 升高。虽然运动后 cEMD 延长且 LV 舒张功能降低，但改变计时赛强度对 cEMD、LV 功能和 cTnI 释放几乎没有影响。
