title: Sleep-related changes in autonomic control in obstructive sleep apnea: a model-based perspective.
abstract: This paper reviews our current understanding of the long-term effects of obstructive sleep apnea (OSA) on cardiovascular autonomic function in humans, focusing directly on the knowledge derived from noninvasive measurements of heart rate, beat-to-beat blood pressure (BP), and respiration during wakefulness and sleep. While heart rate variability (HRV) as a means of autonomic assessment has become ubiquitous, there are serious limitations with the conventional time-domain and spectral methods of analysis. These shortcomings can be overcome with the application of a multivariate mathematical model that incorporates BP, respiration and other external factors as physiological sources of HRV. Using this approach, we have found that: (a) both respiratory-cardiac coupling and baroreflex dynamics are impaired in OSA; (b) continuous positive airway pressure therapy partially restores autonomic function; (c) baroreflex gain, which increases during sleep in normals, remains unchanged or decreases in OSA subjects; and (d) the autonomic changes that accompany transient arousal from NREM sleep in normals are largely absent in patients with OSA.
authors.affiliation: Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA. Electronic address: khoo@bmsr.usc.edu.
authors.forename: Michael C K
authors.initials: MC
authors.lastname: Khoo
authors.forename: Anna
authors.initials: A
authors.lastname: Blasi
mesh_terms: D000465:Algorithms; D000818:Animals; D001341:Autonomic Nervous System / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008959:Models, Neurological; D012890:Sleep / Q000502:physiology*; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*; D013564:Sympathetic Nervous System / Q000503:physiopathology
keywords: Blood pressure; Heart rate variability; Sleep apnea