| Title | Cardiac autonomic activity during daytime nap in young adults. | ||
| Author | Cellini, Nicola; Torre, Jacopo; Stegagno, Luciano; Sarlo, Michela | ||
| Journal | J Sleep Res | Publication Year/Month | 2018-Apr |
| PMID | 28470854 | PMCID | -N/A- |
| Affiliation | 1.Department of General Psychology, University of Padova, Padova, Italy. | ||
The current study investigated both sympathetic and vagal autonomic patterns during a daytime sleep in 25 healthy adults (23.2 +/- 2.4 years). Pre-ejection period (PEP; related inversely to beta-adrenergic sympathetic activity), the interval between consecutive R-waves (RR) and frequency-domain heart rate variability (HRV) were computed during pre-nap wakefulness and undisturbed sleep stages. Results showed sleep-related changes in RR and HRV measures, whereas PEP decreased significantly from pre-nap to sleep, showing no differences across sleep stages. Moreover, pre-nap PEP and HFnu (the normalized unit of the high-frequency component of HRV) were associated negatively with sleep latency and wake after sleep onset. These results indicate a marked autonomic output reduction during daytime sleep, with different stage-dependent fluctuations for sympathetic and vagal activity. Importantly, pre-nap autonomic activity seems to modulate subsequent sleep quality.