Atrial automaticity and atrioventricular conduction in athletes: contribution of autonomic regulation |
| |
Authors: | Ricardo Stein Ruy S Moraes Arthur V Cavalcanti Elton L Ferlin Leandro I Zimerman Jorge P Ribeiro |
| |
Institution: | (1) Cardiology Division, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2350, 90035-007, Porto Alegre, RS, Brazil e-mail: jpribeiro@cpovo.net Tel.: +55-51-3168344; Fax: +55-51-3168657, BR;(2) Biomedical Engineering Division, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2350, 90035-007, Porto Alegre, RS, Brazil, BR;(3) Department of Medicine, Faculty of Medicine, Federal University of Rio Grande do Sul, Rua Ramiro Barcelos 2350, 90035-007, Porto Alegre, RS, Brazil, BR |
| |
Abstract: | 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.
Accepted: 2 January 2000 |
| |
Keywords: | Transesophageal atrial stimulation Sinus node recovery time Wenckebach point Heart rate variability Parasympathetic tone |
本文献已被 PubMed SpringerLink 等数据库收录! |
|