[Changes in autonomic cardiovascular control in biological aging--studies using orthostatic provocation and analysis of heart rate profiles in long-term ECG].

We compared the reactions of heart rate in long-term ECG as well as the heart rates and the blood pressures in orthostatic provocation tests using pharmacological blockades in 14 young human subjects aged 19 to 33 years (mean age = 22 +/- 2.2 years) with those of 16 healthy subjects between 67 and 89 years (m = 74 +/- 9.4 years).