Left ventricular hypertrophy and sinus variability in systemic hypertension

Background: previous studies of heart rate variability (HRV) in systemic hy pertension have yielded conflicting results. We sought to assess the altera tions of HRV in hypertensive patients with or without left ventricular hype rtrophy (LVH). Methods: 195 hypertensive patients in sinus rhythm, mean age 53 +/- 11 year s, without diabetes mellitus, nor symptomatic coronary disease or systolic dysfunction. were prospectively enrolled. Echocardiographic examination all owed their subdivision in 3 groups: normal geometry (112), concentric remod eling (43) and LVH (40). Time and frequency domain measures of HRV were obt ained from 24 h Holter ECG recordings in all patients as in 40 control subj ects. Results: In comparison with control subjects, the 3 hypertensive groups pre sented a significant decrease of SDNN and total frequency power both indexe s of global HRV; a significant decrease of pNN50 and high frequency power, indexes of HRV reflecting parasympathetic tone, and a significant decrease of SDANN and low frequency power, indexes reflecting sympathetic modulation of HRV. Comparisons among the three hypertensive groups showed that patien ts with LVH had significantly (p<0.05) lower low frequency power (5.5<plus/ minus>1.0 Ln rn) than patients with left ventricular normal geometry (5.9 0 .8 Ln m(2)) or concentric remodeling (5.9 +/-0.9 Ln m(2)). Conclusion: assessment of HRV in hypertensive patients shows a constant dec rease of parasympathetic indexes and a more markedly reduction of sympathet ic parameters in presence of LVH.