Stein R, Moraes R S, Cavalcanti A V, Ferlin E L, Zimerman L I, Ribeiro J P
Cardiology Division, Hospital de Clínicas de Porto Alegre, RS, Brazil.
Eur J Appl Physiol. 2000 May;82(1-2):155-7. doi: 10.1007/s004210050666.
Little is known about the sinoatrial automatism and atrioventricular conduction of trained individuals who present a normal resting electrocardiogram. We used transesophageal atrial stimulation, a minimally invasive technique, to evaluate aerobically trained athletes (n = 10) and sedentary individuals (n = 10) with normal resting electrocardiograms, to test the hypothesis that parasympathetic tone, as detected by heart rate variability, could be associated with changes in sinoatrial automatism and atrioventricular conduction. Corrected sinus node recovery time tended to be longer in athletes than in sedentary individuals, but this difference did not reach statistical significance. The Wenckebach point occurred at a lower rate in athletes than in the controls. Over a 24-h period of measurement, the mean RR interval was longer in the athletes than in the sedentary individuals. The mean square root of successive differences (rMSSD) tended to be higher in athletes than in controls, but this difference did not reach statistical significance. There was a moderate correlation (r = 0.48, P < 0.05) between the index of atrioventricular conduction, the rate at the Wenckebach point, and the logarithmically transformed rMSSD. Thus, as a corollary to its effects on the sinus node, where increased parasympathetic tone, decreased sympathetic tone, and non-autonomic components may contribute to sinus bradycardia, it is possible that athletic training may also induce intrinsic adaptations in the conduction system, which could contribute to the higher prevalence of atrioventricular conduction abnormalities observed in athletes.
对于静息心电图正常的受过训练的个体的窦房结自律性和房室传导情况，人们了解甚少。我们采用经食管心房刺激这一微创技术，对静息心电图正常的有氧训练运动员（n = 10）和久坐不动的个体（n = 10）进行评估，以检验心率变异性检测到的副交感神经张力可能与窦房结自律性和房室传导变化相关这一假设。校正后的窦房结恢复时间在运动员中往往比久坐不动的个体更长，但这种差异未达到统计学显著性。文氏点在运动员中的发生率低于对照组。在24小时的测量期间，运动员的平均RR间期比久坐不动的个体更长。连续差值的均方根（rMSSD）在运动员中往往高于对照组，但这种差异未达到统计学显著性。房室传导指标、文氏点频率和对数转换后的rMSSD之间存在中度相关性（r = 0.48，P < 0.05）。因此，作为其对窦房结影响的一个推论，其中副交感神经张力增加、交感神经张力降低和非自主成分可能导致窦性心动过缓，体育训练也有可能在传导系统中诱导内在适应性变化，这可能导致在运动员中观察到的房室传导异常患病率较高。
