RT-71
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Physiological and non physiological vagotonia in athletes and sportsmen: an old problem revisited
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Paolo Zeppilli, Francesco Scarcella, Serena Bria, Antonio Gianfelici, Massimiliano Bianco, Vincenzo Palmieri.
Centro Studi di Medicina dello Sport, Istituto di Medicina Interna e Geriatria, Universita Cattolica, Roma, Italy
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Introduction
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The cardiac autonomic nervous system is capable, with
large flexibility, to mitigate or to amplify the effects of different physiological or pathological
stimula on cardiovascular variables1. Regular aerobic training significantly influences cardiac
autonomic nervous system and sinus bradycardia is the most easily appreciable sign of this
influence. Bradycardia of athletes was thought to be the result of increased sensibility of atrial
cholinergic receptors2, vagal drive
enhancement3 or decrease in sympathetic
discharge4.
Non-neural components are also implicated5 and a decrease in intrinsec heart rate was observed
both in animals and sportsmen6,7.
Recently, a further contribute to this topic was provided by mathematical analysis of beat-to-beat
heart rate signal spontaneous fluctuations (heart rate variability)8. Actually, it represents the most
simple and inexpensive tool to investigate the relative impact of the two cardiac autonomic
components on athlete’s heart in different clinical and experimental conditions. Athletes investigated
in a true “basal condition”, show the prevalence of the respiratory (vagal) high frequency component
of autonomic modulation9-11. The importance to obtain recordings in really basal condition is
demonstrated by the fact that strenuous exercise and/or overtraining may significantly modify the
spectrum heart rate variability9,12.
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Key Words
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