Cardiac autonomic activity during daytime nap in young adults
Interestingly, vagal activity seems to be modulated by sleep even during a daytime nap (Cellini et al., 2016), supporting the idea that naps may be beneficial for cardiovascular health (Naska et al., 2007). However, to date, how sympathetic activity is modulated during a nap and the impact of pre‐nap arousal level on the subsequent sleep remain unknown.
Here we measured cardiac vagal and sympathetic activity concurrently across sleep stages during an afternoon nap in healthy adults. We aimed to: (1) assess the cardiac sympathetic activity across sleep stages during a daytime nap; (2) explore the impact of the pre‐sleep cardiac activity on the subsequent sleep quality; and (3) reproduce previous findings of heart rate variability (HRV) patterns during naps.