[The dynamics of orthostatic cardiovascular immediate and late regulation in healthy adolescents in relation to changed position].

In 16 subjects without any cardiovascular disease the early and the late orthostatic response was tested using the non-invasive continuous blood pressure measurement according to the Penaz principle. The beat to beat analysis of blood pressure revealed an instantaneous blood pressure decrease with standing up from sitting and from squatting; the initial heart rate maximum was markedly delayed against the minimum of mean and pulse pressure. The minimum mean pressure in the finger at the level of diaphragm was 57.8 +/- 14.4 mm Hg, a new steady state-pressure after the change of posture was achieved after about 15 s. The power spectra obtained from 5-minutes samples showed that the respiratory components of cardiac intervals, systolic and pulse pressure decreased markedly in standing. Compared to the control a significant increase of the so-called 10-second-rhythm could be detected.