Heart rate changes during sleep in response to experimental thermal (nociceptive) stimulations in healthy subjects.
OBJECTIVE
During wakefulness, nociceptive thermal stimulation can trigger a rapid and transient rise in heart rate (HR). During sleep, HR variations are different across sleep stages; HR is more variable in stage 2 and in REM than in stages 3 and 4. The aim of this study was to assess the HR response to experimental thermal stimulation during different sleep stages.


METHODS
Eight young subjects free of sleep and pain problems, underwent a night of polysomnographic recording during which experimental thermal stimulations were applied. During all sleep stages (St), a series of cold, warm/control and heat pain stimulations were applied over the shoulder skin by means of a water-driven system. Variation of HR interval was measured for 6 s before and for 6 s during the thermal stimulation.


RESULTS
In comparison to control warm stimulation, experimental nociceptive thermal stimulation induced a significant rise in HR during sleep; HR increased by 7% in St 2, 5.4% in St 3&4, and by 4.3% in REM sleep.


CONCLUSIONS
The brief increase in cardiac activity with experimental nociceptive stimulation suggests that during sleep, the autonomic-cardiac nervous system remains reactive to external sensory inputs and is part of the physiological response to preserve body safety and sleep integrity in the face of potentially harmful stimulation.
Sleep studies Centre/Hôpital du Sacré-Coeur and Faculty of Dental Medicine, Université de Montréal, C.P. 6128, Succursale Centre-ville, Québec H3C 3J7, Montréal, Canada. gilles.lavigne@umontreal.ca
G J
GJ
Lavigne
M
M
Zucconi
V
V
Castronovo
C
C
Manzini
F
F
Veglia
S
S
Smirne
L
L
Ferini-Strambi
D000328:Adult; D001341:Autonomic Nervous System / Q000502:physiology; D005260:Female; D006321:Heart / Q000294:innervation / Q000502:physiology; D006339:Heart Rate / Q000502:physiology*; D006358:Hot Temperature; D006801:Humans; D008297:Male; D009619:Nociceptors / Q000502:physiology*; D010146:Pain / Q000503:physiopathology*; D017286:Polysomnography; D012894:Sleep Stages / Q000502:physiology*