Agreement Between ECG-Derived Heart Rate Variability and Finger-PPG Pulse Rate Variability During Rest: A Dual-Sensor Study Using Polar H10 and LifePulsePro

Background. Finger photoplethysmography (PPG) permits brief measurements of pulse rate variability (PRV), although pulse intervals and ECG R–R intervals represent different physiological events. Objective. To assess the agreement of Polar H10 R–R intervals with LifePulsePro finger pulse intervals at rest, examine time-domain HRV/PRV and repeatability, and explore ECG-to-finger pulse arrival time (PAT) and a derived velocity index in relation to age and sex. Methods. Twenty-five three-minute recordings obtained from 13 volunteers during quiet seated rest were evaluated. Five thousand two hundred forty-four accepted ECG–PPG interval pairs were recalculated from the synchronized interval exports. Repeated measurements were averaged within volunteer for inferential analysis. Results. Volunteer-level mean absolute interval error was 5.23 ms (95% CI 4.53–5.93), with mean within-record correlation r=0.965 (95% CI 0.947–0.983) and signed bias +0.010 ms (p=0.760). PPG SDNN and RMSSD exceeded ECG values by 4.73% and 15.22%, respectively. MAE test–retest ICC(3,1) was 0.85. Mean PAT-foot was 182.2 ms and the protocol-specific velocity index vPAT averaged 5.05 m/s (95% CI 4.75–5.34). Eleven of 13 volunteer values were at or below the application’s preliminary age-group medians. Conclusions. Finger PPG preserved beat-to-beat timing closely during quiet rest, but time-domain PRV indices showed measurable positive bias, especially RMSSD. PAT and vPAT can be described with the dual-sensor system; they require independent vascular validation before clinical interpretation.