title: Firing patterns of muscle sympathetic neurons during apnea in chronic heart failure patients and healthy controls.
abstract: In the present study we investigated the influence of end-expiratory breathing cessation on firing activity of muscle sympathetic fibers in 6 stable chronic heart failure (CHF) patients and in 6 healthy age and gender matched controls. Integrated multi-unit bursts, as well as action potentials (APs), were identified from multi-unit muscle sympathetic nerve activity (MSNA) recordings during baseline and during functional residual capacity (FRC) apnea. Compared with controls, CHF patients had higher burst frequency and AP firing frequency (P<0.05) at baseline. FRC apnea caused an increase in the number of APs per multi-unit sympathetic burst, in the AP frequency (P<0.05) and in the number of active clusters per multi-unit sympathetic burst in both groups (controls P<0.06, CHF group P=0.1). The data suggest a comparable pattern of sympathetic activation associated with breath hold in healthy middle-aged individuals and in stable CHF patients. Thus, recruitment patterns for this stress are not affected by CHF despite their elevated sympathetic state.
authors.affiliation: Department of Physiology, University of Split School of Medicine, Soltanska 2, 21000 Split, Croatia.
authors.forename: Petra
authors.initials: P
authors.lastname: Zubin Maslov
authors.affiliation: Neurovascular Research Laboratory, School of Kinesiology, Western University, London, Ontario, Canada; Department of Physiology and Pharmacology, Western University, London, Ontario, Canada.
authors.forename: J Kevin
authors.initials: JK
authors.lastname: Shoemaker
authors.affiliation: Department of Physiology, University of Split School of Medicine, Soltanska 2, 21000 Split, Croatia. Electronic address: zeljko.dujic@mefst.hr.
authors.forename: Zeljko
authors.initials: Z
authors.lastname: Dujic
mesh_terms: D000200:Action Potentials / Q000502:physiology; D062485:Breath Holding; D005260:Female; D005652:Functional Residual Capacity / Q000502:physiology; D006333:Heart Failure / Q000503:physiopathology*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology; D010543:Peroneal Nerve / Q000503:physiopathology*; D012891:Sleep Apnea Syndromes / Q000503:physiopathology; D013564:Sympathetic Nervous System / Q000503:physiopathology*
keywords: Action potential detection; Cardiovascular disease; Sleep apnea