The Role of Heart Rate Variability in Atrial ECG Components of Normal Sinus Rhythm and Sinus Tachycardia Subjects

Abstract

Heart Rate Variability (HRV) is a biological process that indicates any disturbances in the time duration between heartbeats. It is quantified by the number of disturbances in beat to beat interval and the contrast observed in heart rate may indicate various cardiac diseases. This study aims to delineate the role of HRV in Normal Sinus Rhythm (NSR) and Sinus Tachycardia (ST) subjects of atrial ECG components. Hundred young healthy individuals (20 women) of mean age (28 ± 5.36) were included in this study. ECGs were recorded in supine position using the EDAN SE-1010 PC ECG system. The mean atrial rate of NSR subjects is 87 ± 7.7 beats per minute (bpm) and 108 ± 4.2 bpm for ST subjects. The mean P wave duration for NSR and ST subjects is 96 ± 8.5 ms and 87 ± 18.6 ms, PR interval is 139 ± 17.4 ms and 107 ± 18.6 ms, and PP interval is 718 ± 56 ms and 534 ± 41 ms, respectively. Atrial sinus cycle length (PP interval) and HRV mainly affected the repolarization segment in ST subjects than the NSR subjects.