[A study of cardiac dynamics during multistage exercise tests performed on a bycicle ergometer (author's transl)].

The authors analysed the behaviour of the mechanical systole (electromechanical systole; tension time, left ventricular ejection time), as well as of the diastole (both cardiac and hemodynamic diastole) during exercise tests performed on a bycicle ergometer, with 40, 80, 120 watt workloads. The mechanical systole--as well as its components--duration is influenced, during exercise test, by both heart rate and stroke volume--pulse pressure being assumed as an indirect index of the latter. The study of the correlation between the two above mentioned parameters has a great importance in evaluating the cardiac pump efficiency both in health and disease. The study of the behaviour of diastole is likewise very important, as it provides useful information concerning: a) the length of the cardiac muscle post-exercise recovery phase; b) the coronary available perfusion time; c) the Windkessel (arterial bellows) emptying time. Moreover, the blood pressure fall rate in diastole is an useful indirect measure of the peripheral resistance changes during muscular work. A statistical analysis is made and the correlation coefficients and the regression equations between the various parameters are defined.