Abstract des Autors

This study aims to determine the influence exerted by physical exercise and corporeal growth on the cardiovascular system of young athletes in the age of development. Fifty-two young agonist footballers in prepubertal (group A) and pubertal age (group B) were submitted to the following schedule: general examination with medical history and collection of anthropometric data; electrocardiogram at rest, during step-test and during recovery (ECG); echocardiogram M and 2 D (ECO). The same schedule was applied to 22 control subjects, both prepubertal (group C) and pubertal (group D), none of them taking part in any regular sport. In all cases the ECG was analyzed for: Heart Rate (FC), Sokolow-Lyon Index and possible presence of anomalies which are considered typical of athletes, such as: interval PR>/=0.20, early repolarization, minor disturbances of right intraventricular conduction: cardiac dimensions were measured at ECO. In young footballers FC was significantly lower in comparison to controls, both at rest (63.6+/6,5 b/min in group A, vs 66.7+/-7.0 b/min in group C, p<0.01; 61.3+/-6.1 b/min in group B vs 64.5+/-6.5 b/min in group D, p<0.01), and after step-test (at min 1 of recovery: 90.6 b/min in group A vs 93.4 b/min in group C, p<0.01; 85.3 b/min in group B vs 90.2 b/min in group D, p<0.01) and a higher incidence of electrocardiographic anomalies typical of athletes was recorded. The Sokolow-Lyon Index was significantly higher in athletes in comparison to controls (42.14+/-8.5 in group A vs 38.5+/-6.5 in group C, p<0.01; 46.52+/-9.0 in group B vs 41.72+/-6.0 in group D, p<0.01). Echocardiography showed, in trained subjects, a tendency towards the increase in cardiac dimensions. The thickness of the walls appeared to increase more in respect to cavitary diameters, (Interventricular septum: group A 7.8+/-0.4; group C 7.2+/-0.9, p<0,05; group B 10.1+/-0.6; group D 8.6+/-0.9, p<0.01. Telediastolic diameter: group A 46.3+/-1.9; group C 43.9+/-2.6, p<0.03; group B 49.9+/-2.0; group D 48.2+/-2.1, p<0.01). In conclusion, this study shows that the effect of training is additive to that of growth upon the modifications of the cardiovascular system, particularly with regard to the development of ventricular walls and the electrocardiographic indexes of hypertrophy during the phase of pubertal growth. Verf.-Referat