[Variability of arterial pressure and heart rate measured at two periods of 15 minutes to 15 days intervals].

Intra individual blood pressure (BP) and heart rate (HR) variations and their possible correlation with sex and age were evaluated in 271 healthy adults, adolescents and children divided into equivalent groups of both sexes. BP and HR were measured every minute during 14 minutes with an automatic device using the oscillometry method. A second measurement session was repeated two weeks later. On most patients, a decrease of BP was observed during the first minutes towards a point of relative stability, which is reached after the eighth measurement. Mean differences between the first and the fourteenth minutes is about 12 mmHg for systolic BP and 18 mmHg for diastolic BP. The mean values of the 14 determinations on day 1 and day 15 showed a significant correlation from 65 to 75 according to different groups. The variability index within one subject was almost similar in all groups. A comparison of the variability indices observed on day 1 and day 15 showed a significant correlation only for systolic BP in male and for HR in female subjects. Reproducibility of variability appears very inconstant. The results suggest that this procedure cannot characterize subjects with a high BP variability. This study suggests that fourteen repeated measurements of BP values over a fortnight period allows a better estimation of BP level at rest. It cannot be equivalent to 24 hour BP record to estimate variability.