Non-Interchangeability between Heart Rate Variability and Pulse Rate Variability During Supine-to-Stand Tests

TL;DR

This study investigates whether pulse rate variability (PRV) can reliably replace heart rate variability (HRV) during supine-to-stand tests, revealing significant differences and questioning their interchangeability in postural change assessments.

Contribution

It provides empirical evidence that PRV and HRV are not interchangeable during posture transitions, highlighting the physiological differences in their measurement.

Findings

PRV differs significantly from HRV during supine-to-stand tests.

Discrepancies between PRV and HRV increase during posture transitions.

Both metrics reflect sympathetic activation but are not interchangeable.

Abstract

Heart rate variability (HRV) is widely recognized as a valuable biomarker for assessing autonomic cardiac regulation. Pulse rate variability (PRV) is a common surrogate of HRV given the wide usability of PPG in commercially available devices. However, there is no clear conclusion on whether PRV can replace HRV given their different physiological mechanisms. This study evaluates the interchangeability of young adults HRV and PRV during supine-to-stand (STS) tests which are known as common posture transitions in daily life monitoring. Fifteen features from time, frequency and nonlinear domains were extracted from both electrocardiography and PPG signals. Paired t-tests and Wilcoxon signed-rank tests examined the difference between the extracted HRV and PRV features during supine, transition and standing phases separately. One feature showed significant difference in the supine phase, and this discrepancy increased to four in the transition and standing phases. These findings suggested that PRV is different from HRV in the STS tests, despite the fact that both metrics can reflect the sympathetic activation triggered by the posture changes.