[Mechanisms controlling blood pressure and heart rate variability: physiological and physiopathological aspects]

These studies explore the mechanisms controlling the 24-hour, the ultradian and the instantaneous variability in blood pressure and RR interval in humans. Several studies are undertaken to determine the contribution of environment, genetics, sleep-wake cycle and specific sleep stages on the blood pressure and RR interval variability in normal subjects. The analysis of the effects of cardiac failure, of renal failure and of organ transplantation provides further information on the mechanisms controlling blood pressure and RR interval variability in pathological conditions.