Left ventricular hypertrophy and sinus variability in arterial hypertension

Abstract

Previous studies on heart rate variability (HRV) in systemic hypertension have yielded conflicting results. We sought to assess changes in HRV in hypertensive patients with or without left ventricular hypertrophy (LVH). In total, 112 patients with sinus rhythm hypertension, mean age 56 ± 10 years, without diabetes mellitus, symptomatic coronary artery disease or systolic dysfunction, were recruited prospectively. Echocardiographic examination allowed them to be subdivided into 3 groups: normal geometry (71), concentric remodeling (23) and LVH (18). HRV time and frequency domain measurements were obtained from 24-hour Holter ECG recordings in all patients and in 40 control subjects. In comparison with control subjects, the 3 hypertensive groups exhibited a significant decrease in SDNN and total frequency power, the two indices of overall HRV; a significant decrease in pNN50 and power at high frequency, indices of HRV reflecting parasympathetic tone, and a significant decrease in SDANN and power at low frequency, indices reflecting sympathetic modulation of HRV. Comparisons between the three hypertensive groups showed that patients with LVH had significantly ( P < 0.05) lower low frequency power (5.5 ± 1.0 Ln m2) than patients with normal left ventricular geometry. (5.9 ± 0.8 Ln m2) or a concentric remodeling (5.9 ± 0.9 Ln m2). Evaluation of HRV in hypertensive patients shows a constant decrease in parasympathetic indices and a more marked reduction in sympathetic parameters in the presence of LVH.