The Pulse-Respiration Quotient: A Powerful but Untapped Parameter for Modern Studies About Human Physiology and Pathophysiology

This study only analyzed the PRQ phases that showed a constant PRQ over a specific period (frequency coupling) and also a phase entrainment between HR and RR (phase coupling) during this time. During sleep, a complex correlation between the HR and the RR is evident with the PRQ capturing one specific aspect. In a study investigating the N-rs-PRQ with a detailed division of the sleep stages (five stages), Zerm et al. (2008) showed that there is a positive correlation between the N-rs-PRQ and the sleep depth, i.e., the higher the depth of sleep, the lower the N-rs-PRQ. In this study, sleep depth was defined according to the scale “awake → REM → non-REM I–II → non-REM III–IV.” A lower N-rs-PRQ value during deep sleep than REM sleep (3.83 ± 0.59 vs. 4.12 ± 0.74) was also found by von Bonin et al. (Von Bonin et al., 2014). These two findings seem to contradict the finding of Bartsch et al.; however, Bartsch et al. determined the N-rs-PRQ only when there was a phase entrainment between HR and RR – in contrast to Zerm et al. who determined the N-rs-PRQ continuously. •  The subjectively perceived sleep quality correlates negatively with the mean N-rs-PRQ, i.e., subjects rated the quality of their sleep lower when the N-rs-PRQ was higher (Zerm et al., 2008). •...
Source: Frontiers in Physiology - Category: Physiology Source Type: research