[Evaluation of the aging change in cardiac autonomic nervous system by automated clinical measurement].

The object of this study was to establish normal values for age of clinical tests of autonomic nervous system activity based on an automatic measuring system. Ninety-seven subjects (50 M/47 F) aged 20 to 85 years (average 45 +/- 13 years) with a normal clinical examination and no medication were included in the study. The blood pressure (BP) and heart rate (HR) were measured continuously with the Finapres system. After a resting period, the BP and HR were measured continuously in 5 different situations: dorsal decubitus position for 7 minutes; on getting up actively in less than 3 seconds and for 9 minutes in the upright positions, during deep breathing at 6c/min and Valsalva manoeuvre during a handgrip test at 30% of maximal voluntary strength for 3 minutes. A specific programme (ISN-CNRS) initiated the calculations of the test and performed direct and crossed spectral analysis in the lying and standing positions. The average BP was 120 +/- 18/66 +/- 11 mmHg and HR was 67 +/- 9 b/min. A negative linear correlation was observed with age with respect to the 3 tests investigating vagal activity: 30/15 ratio, spontaneous variations of respiration and HR, ratio of HR at the end of Valsalva with r = -0.43, r = -0.60, r = -0.34 (p < 0.001). The other two tests: variation of systolic BP 1 min 30 after standing and variation of diastolic BP during the handgrip did not change with age.(ABSTRACT TRUNCATED AT 250 WORDS)