Abstract

Background: Hypertension is one of the most preventable risk factor associated with premature death worldwide. Blood pressure regulation involves multiple mechanisms with autonomic nervous system has a prominent role. The present study focus on the early changes during pathogenesis of essential hypertension in autonomic nervous system. The data acquisition includes short term ECG for 5 minutes from hypertensives and controls with standard protocols. The frequency domain analysis has been done to compare the two groups.

Study Objective: The aim of the study was to compare frequency domain measures of heart rate variability in newly diagnosed essential hypertensives with controls.

Design: Observational analytical case control study.

Setting: The study was conducted in the Department of Physiology, SMS Medical College, Jaipur

Sample / Population: Simple random sampling was done. Seventy newly diagnosed hypertensives from Medical OPD of SMS Hospital, Jaipur and seventy normotensives from employees of SMS Medical College, Jaipur were enrolled in the study.

Duration of Study: April 2017 to November 2018.

Results: In frequency-domain analysis, power in  high frequency [HF (ms2)] and [HF (nu)], which reflects parasympathetic activity, were significantly less in newly diagnosed hypertensive subjects while LF (nu) and LF/HF (%), which reflects sympathetic activity, were significantly higher in newly diagnosed hypertensive subjects as compared to normotensives.

Conclusion: These findings suggest that heart rate variability is reduced in subjects with newly diagnosed essential hypertension and the parasympathetic inhibition and sympathetic activation is present in the early stages of essential hypertension.

Keywords: heart rate variability, hypertension, frequency-domain analysis.