A Statistical Comparison of Heart Rate Variability Measurements Between Devices: Chest Strap Versus Finger Probe.

Heart rate variability (HRV) between R-R intervals results from complex interactions between respiratory activity and autonomic cardiovascular control. Measurements of HRV are strong predictors of cardiac morbidity and mortality. A finger probe is more convenient than a chest strap device so we compared the HRV measurements between the CorSense finger probe and the Polar H7 chest strap. This data was collected in our clinical study (NCT04121741) of 33 subjects (mean age 69 with standard deviation 10, 52% female) with coronary heart disease. We captured HRV in both the time-domain (root mean square of successive RR interval differences (rMSSD), standard deviation of NN intervals (SDNN), percentage of successive RR intervals that differ by more than 50 ms (PNN50)) and the frequency-domain (low-frequency power (LF Power) and high-frequency power (HF Power)). Regression analyses and the Wilcoxon signed-rank-test (WSRT) showed a closer correlation between devices for SDNN and LF Power. However, none of these metrics met the satisfactory agreement criteria. The clinical study had singing and non-singing control sessions. Due to possible discrepancies while singing, we only included non-singing control sessions.