Welsh R C, Haykowsky M J, Taylor D A, Humen D P, Dzavik V
Faculty of Physical Education and Recreation, and Division of Cardiology, University of Alberta, Edmonton, Canada.
Med Sci Sports Exerc. 2000 Jul;32(7):1208-13. doi: 10.1097/00005768-200007000-00004.
The primary purpose was to evaluate the prevalence of late potentials (LPs) in triathletes before and after a half ironman triathlon. The secondary purpose was to examine whether LPs are the electrocardiographic expression of a greater myocardial mass.
Nine asymptomatic male triathletes (mean age +/- SD, 32 +/- 5 yr) were examined using signal-averaged ECG (SAECG) 48-72 h before (PRE), immediately after (POST), and 24-48 h after the completion (RECOVERY) of a half ironman triathlon. Late potentials were considered to be present if two of the following SAECG anomalies were observed: 1) a prolonged filtered QRS (/QRS) complex (> or = 114 ms), 2) a lengthened low amplitude signal (LAS) duration (>38 ms), and/or 3) a low root mean square (RMS) voltage of the last 40 ms of the fQRS (<20 microV). Left ventricular dimensions were determined at PRE using M-mode echocardiography.
There were no significant differences between PRE, POST, and RECOVERY in the fQRS duration, the LAS duration, or the RMS voltage. Two athletes displayed a single SAECG abnormality during PRE and two SAECG anomalies (i.e., LPs) during POST. Late potentials remained in one of the two athletes during RECOVERY. A moderate relationship existed between fQRS and left ventricular mass (r = 0.67, P < 0.05).
Ultra-endurance training and/or events do not lead to LPs in the majority of triathletes who do not possess ventricular arrhythmias. However, a small subset of triathletes do display SAECG anomalies, which are augmented by an ultra-endurance event and may persist even after recovery from the event. Left ventricular mass does not affect overall SAECG parameters.
主要目的是评估半程铁人三项赛前后铁人三项运动员晚期电位（LPs）的患病率。次要目的是研究晚期电位是否为更大心肌质量的心电图表现。
对9名无症状男性铁人三项运动员（平均年龄±标准差，32±5岁）在半程铁人三项赛开始前48 - 72小时（PRE）、结束后立即（POST）以及结束后24 - 48小时（RECOVERY）进行信号平均心电图（SAECG）检查。如果观察到以下SAECG异常中的两项，则认为存在晚期电位：1）滤波后QRS（fQRS）波群时限延长（≥114毫秒），2）低振幅信号（LAS）持续时间延长（>38毫秒），和/或3）fQRS最后40毫秒的均方根（RMS）电压低（<20微伏）。在PRE时使用M型超声心动图测定左心室尺寸。
PRE、POST和RECOVERY在fQRS时限、LAS持续时间或RMS电压方面无显著差异。两名运动员在PRE时出现单一SAECG异常，在POST时出现两项SAECG异常（即晚期电位）。在RECOVERY期间，两名运动员中的一名仍存在晚期电位。fQRS与左心室质量之间存在中度相关性（r = 0.67，P < 0.05）。
超耐力训练和/或赛事不会导致大多数无室性心律失常的铁人三项运动员出现晚期电位。然而，一小部分铁人三项运动员确实会出现SAECG异常，这些异常会因超耐力赛事而加重，甚至在赛事恢复后仍可能持续存在。左心室质量不影响整体SAECG参数。
