The study on circadian rhythm of cardiac autonomic nervous activity and the intervention with enalapril in stage I to II essential hypertensives

Abstract

Objectives: To study the circadian rhythm of cardiac autonomic nervous activity (ANA) in essential hypertension and observe the effect of treatment with enalapril on it. Methods: 24h heart rate power spectral analysis (HRPSA) and 3D HRPS graph were performed in 30 pre-and-post treatment patients with stage I to II essential hypertension (EH I–II). 153 patients with EH I–II, 40 patients with EH III and 30 healthy normotensives. Results: (1) In EH I–II group, TP, VLF, LF and HF were higher apparently (P<0.05) at late night (3–4 am) than those of normotensive group, whereas LF/HF had no difference (P>0.05) between two groups in every interval.