A study on analysis of Heart Rate Variability in hypertensive individuals

Abstract

Introduction: Hypertension is a major risk factor for coronary artery disease, stroke and heart failure. Autonomic nervous system (ANS) dysfunction is an important factor in the development and progression of hypertension. Heart rate variability (HRV) is a simple, sensitive and non-invasive tool to monitor the cardiovascular ANS function. Thus, the present study was chosen as a simple tool to assess the sympathovagal balance by analysing the HRV changes in hypertensive individuals. Aims and Objectives: To analyse Heart Rate Variability (HRV) in hypertensive individuals. Materials and Methods: The study was conducted on 30 normotensive and 30 hypertensive subjects (BP≥140/90 mm Hg, according to JNC-7 classification). Lead-II ECG was recorded using the instrument PHYSIOPAC-PP4, MEDICAID system, Chandigarh and HRV analysis was done using Kubios HRV analyser. Spectral indices of HRV such as total power (TP), normalized low frequency power (LFnu), normalized high frequency power (HFnu), ratio of low frequency power to high frequency power (LF-HF ratio), standard deviation of normal-to-normal RR intervals (SDNN), root mean square successive difference (rMSSD) and the proportion of NN50 to the total number of NN intervals (pNN50) were assessed. Results: Our results showed significantly reduced HFnu (p 0.05), SDNN (p 0.05), rMSSD (p 0.05) and pNN50 (p 0.05) in hypertensive individuals. LFnu and LF-HF ratio was significantly increased (p 0.05) in hypertensive individuals.