Dynamic ventilatory response to CO2 in congestive heart failure patients with and without central sleep apnea

• Published in: Journal of applied physiology (1985) 2001-07, Vol.91 (1), p.408-416
• Main Authors: Topor, Zbigniew L, Johannson, Linda, Kasprzyk, Jerzy, Remmers, John E
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Carbon dioxide; Cardiology. Vascular system; Comparative analysis; Heart; Heart failure; Heart failure, cardiogenic pulmonary edema, cardiac enlargement; Medical sciences; Patients; Respiratory system; Sleep disorders
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/jappl.2001.91.1.408

1  Center for Biomedical Engineering, University of Kentucky, Lexington, Kentucky 40506; 2  Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1; and 3  Institute of Automatic Control, Silesian Technical University, 44-101 Gliwice, Poland Nonobstructive (i.e., central) sleep apnea is a major cause of sleep-disordered breathing in patients with stable congestive heart failure (CHF). Although central sleep apnea (CSA) is prevalent in this population, occurring in 40-50% of patients, its pathogenesis is poorly understood. Dynamic loop gain and delay of the chemoreflex response to CO 2 was measured during wakefulness in CHF patients with and without CSA by use of a pseudorandom binary CO 2 stimulus method. Use of a hyperoxic background minimized responses derived from peripheral chemoreceptors. The closed-loop and open-loop gain, estimated from the impulse response, was three times greater in patients with nocturnal CSA ( n  = 9) than in non-CSA patients ( n  = 9). Loop dynamics, estimated by the 95% response duration time, did not differ between the two groups of patients. We speculate that an increase in dynamic gain of the central chemoreflex response to CO 2 contributes to the genesis of CSA in patients with CHF. central chemosensitivity; pseudorandom binary stimulation; impulse response; dynamic loop gain; carbon dioxide