Association of Heart rate variability measured by RR interval from ECG and pulse to pulse interval from Photoplethysmography

BackgroundHeart rate variability (HRV) is a reliable diagnostic tool for the evaluation of autonomic dysfunction. The pattern of Heart rate reflects on pulse rate. So Pulse rate variability (PRV) is a sensitive indicator of the autonomic tone similar to HRV. The current study aimed to compare PRV measured from pulse plethysmography (PPG) with HRV recorded from ECG.Materials and MethodsThe study was executed in 50 healthy female volunteers aged 18–25 years. The simultaneous recording of lead II ECG and PPG in two channels through audacity software was done for all subjects. Later the R-R interval calculated separately for ECG and Pulse to pulse interval (PRV) from PPG were estimated, and HRV parameters were obtained using Kubios software.ResultsR-R interval mean from ECG (700 ± 81.34msec) and PRV (703.6 ± 86.28msec) were similar and had a significant positive correlation (r = 0.99). Time-domain parameters SDNN (r = 0.61), RMSSD (r = 0.78), NN50 (r = 0.790 and pNN50 (r = 0.92) also has strong positive correlation between the HRV and PRV. Similarly frequency domain, LF Power (r = 0.79), HF power (r = 0.75), LF in n.u (r = 6.0), HF in n.u (r = 5.1) also showed very strong correlation. Bland Altman plot reflected a good agreement between the methods for time and frequency domain parameters.ConclusionThe current study shows that the two methods’ values are similar, consistent, and reproducible between HRV and PRV. It suggests PRV can also evaluate sympathovagal balance in different clinical conditions along with HRV in a large community-based study.