[Analysis of variations in cardiac performance induced by tilt and hand-grip in athletes and in untrained subjects].
The aim of the present study is to analyze variations of external cardiac work and of indices of myocardial oxygen consumption induced by upright tilting and hand-grip in volley-ball athletes (group A) in comparison with a group of normal subjects (group N). For this purpose we have used impedance cardiography, a simple, reproducible and non invasive technique, which is very reliable in evaluating both systolic time intervals and hemodynamic parameters such as stroke volume and cardiac output. No significant differences, of external cardiac work, double and triple product were observed between group A and N upon upright tilting. Hand-grip test, on the other hand, can differentiate the myocardial behaviour of trained people from that of the control group. The double product was significantly reduced in group A in comparison with group N (P less than 0.001 and the end of the test, P less than 0.05 after 30", P less than 0.001 after 1' and 3"). The triple product was significantly reduced in group A in comparison with group N at the end of the test (P less than 0.005). External cardiac work was always higher in group A in comparison with group N (P less than 0.02, at the stop P less than 0.05 after 30", P less than 0.01 after 1', P less than 0.0001 after 3'). Therefore in volleyball athletes the myocardium exhibits better mechanical performance than in normal subjects.
D001794:Blood Pressure; D002320:Cardiovascular Physiological Phenomena; D006225:Hand / Q000502:physiology; D006321:Heart / Q000502:physiology; D006339:Heart Rate; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D009119:Muscle Contraction; D010101:Oxygen Consumption; D010809:Physical Fitness; D011187:Posture; D013177:Sports; D013318:Stroke Volume; D013599:Systole
Analisi delle variazioni del rèndimento cardiaco indotte dal tilt e dall'hand-grip in atleti ed in soggetti non allenati.