Correlation of heart rate with heart rate variability in sedentary young Indian women

Abstract

Background: Autonomic nervous system (ANS) provides physiological balance in our body by regulating many bodily functions through its sympathetic and parasympathetic branches. Heart rate variability (HRV) is noninvasive method to assess ANS control at sinoatrial node of heart. HRV is derived from variations in heart rate (HR) over time through RR intervals. Aim: This study aims to investigate the correlation between HR and time and frequency domain indices of HRV. Materials and Methods: The study included 32 sedentary young women (20–24 years) from Jamia Millia Islamia, India. Twenty minutes electrocardiograph (ECG) recording was done for HRV analysis and 6 seconds ECG was recorded for HR measurement. Time domain indices of HRV such as SDNN, RMSSD, PNN50, and frequency domain indices of HRV such as total power, low-frequency (LF) power, high-frequency (HF) power, and LF/HF ratio were obtained. Results: There was significant inverse correlation between HR and RMSSD (P = 0.03, r = −0.37) and PNN50 (P = 0.003, r = −0.49) and total power (P = 0.02, r = −0.39). SDNN (P = 0.82, r = −0.03), HF power (P = 0.55, r = −0.10) showed nonsignificant inverse correlation trends with HR. LF power (P = 0.62, r = 0.09) and LF/HF ratio (P = 0.81, r = 0.04) demonstrated nonsignificant linear correlation trend with HR. Conclusion: The findings of this study demonstrated that there is an inverse correlation between HRV and HR of sedentary young women. Lower HR is associated with higher HRV and vice versa. Therefore, HR should be taken into consideration when recording HRV. HR may act as a method to quickly assess the function of ANS.