Intracerebroventricular propranolol prevented vascular resistance increases on arousal from sleep apnea

Sophia Zinkovska and Debra A. Kirby Children's Hospital, Harvard Medical School, Boston 02115; and Veterans Affairs Medical Center, West Roxbury, Massachusetts 02132 Received 19 July 1995; accepted in final form 19 November 1996. Zinkovska, Sophia, and Debra A. Kirby. Intracerebroventricular propranolol prevented vascular resistance increases on arousal from sleep apnea. J. Appl. Physiol. 82(5): 1637-1643, 1997. Despite the increased risk of sudden cardiac death associated with sleep apnea, little is known about mechanisms controlling cardiovascular responses to sleep apnea and arousal. Chronically instrumented pigs were used to investigate the effects of airway obstruction (AO) during rapid-eye-movement (REM) and non-REM (NREM) sleep and arousal on mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), and total peripheral resistance (TPR). A stainless steel cannula was implanted in the lateral cerebral ventricle. During REM sleep, HR was 133 ± 10 beats/min, MAP was 65 ± 3 mmHg, CO was 1,435 ± 69 ml/min, and TPR was 0.046 ± 0.004 mmHg · ml 1 · min. During AO, CO decreased by 90 ± 17 ml/min ( P