Cardiorespiratory transfer during sleep : a study in healthy young men. Borne, Philippe Van De, Patrick Biston, Manuel Pa[diaeresis]iva, Hung Nguyen, Paul Linkowski, Jean-Paul Degaute. Hypertension Clinic, Institute of Interdisciplinary Research and Sleep Laboratory, Department of Psychiatry. H[circumflex]opital Erasme, Universit[acute]e Libre de Bruxelles, Brussels, Belgium.
APStracts 2:0107H, 1995.
This study tested the concept that changes in breathing parameters account for modifications in respiratory related blood pressure (BP) and RR interval (RRI) variability during nocturnal sleep. Blood pressure (Finapres_), electrocardiogram, respiration (Respitrace _) and polygraphic sleep recordings were recorded continuously in 13 healthy men aged 18-37 years. The transfer characteristics identified by coherence and gain measures between the calibrated thoraco -abdominal motion and the respiratory related BP and RRI variability evidenced a consistent increase during transitions from wake to light sleep; from light to deep sleep; but returned to the waking levels during rapid-eye-movement sleep (p < 0.0001). These changes were related to the specific modifications occuring in the respiratory rate, tidal volume and ribcage/abdominal motion ratio during the different sleep stages (0.28 < r < 0.39; p < 0.0001). This study demonstrates first, that modifications in the breathing pattern account for 8 to 15 % of the variance in the cardiorespiratory transfer and second that respiratory modulation of vagal activity is not the main mechanism controlling the magnitude of the respiratory related BP and RRI variability during sleep. 

Received 16 December 1994; accepted in final form 16 March 1995.
APS Manuscript Number H1101-4.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on  4 April 1995.