Modulations of human autonomic function induced by positive pressure-assisted breathing

• Published in: Clinical physiology and functional imaging 2006-01, Vol.26 (1), p.15-20
• Main Authors: Garet, Martin, Barthélémy, Jean-Claude, Degache, Francis, Pichot, Vincent, Duverney, David, Roche, Frédéric
• Format: Article
• Language: English
• Subjects: Adult; autonomic nervous system; Autonomic Nervous System - physiology; Baroreflex - physiology; Biological and medical sciences; Blood Pressure - physiology; Blood vessels and receptors; cardiac baroreflex sensitivity; Electrocardiography; Female; Fundamental and applied biological sciences. Psychology; Heart Rate - physiology; heart rate variability; Humans; Male; positive airway pressure; Positive-Pressure Respiration; ventilation; Vertebrates: cardiovascular system
• ISSN: 1475-0961; 1475-097X
• DOI: 10.1111/j.1475-097X.2005.00645.x

Summary In order to examine the acute autonomic response in humans during and immediately after positive pressure‐assisted (PPA) breathing, spontaneous cardiac baroreflex (BR) sensitivity was studied through the adaptation of consecutive RR intervals in response to spontaneous systolic blood pressure fluctuations in 11 healthy subjects. The gain (α‐index) in baroreceptor reflex was estimated using cross‐spectral analysis (RR interval variability and systolic blood pressure variability) for the low frequency (LF) and high frequency (HF) bands. All measurements were made under fixed breathing rate (12 breaths per minute), and realized consecutively at baseline level (20 min), after‐short inspiratory pressure support plus positive end‐expiratory airway pressure (IPS + PEEP) ventilation (15 min), again under normal conditions (20 min; recovery period) and, finally, during a standard upward orthostatic challenge test (15 min; orthostatic challenge). The spontaneous BR gain in the HF band increases slightly during ventilation (+26·1 ± 11·7%, P