Sleep stage-dependent heart rate variability in patients with obstructive sleep apnea

Heart rate variability during sleep is under the control of the autonomous system. During sleep the parasympathetic activity is elevated and sympathetic activity is lower. Sleep related breathing disorders, such as obstructive sleep apnea change the normal balance of the autonomous nervous system during sleep. New random-walk type methods of analysis allow to distinguish the different modes of regulation in the different sleep stages and in addition allow to detect sleep related changes in heart rate variability.