Vagal tone is reduced during paced breathing in patients with the chronic fatigue syndrome

Abstract

Patients with chronic fatigue syndrome (CFS) often complain of an inability to maintain activity levels and a variety of autonomic-like symptoms that make everyday activity intolerable at times. The purpose of the study was to determine if there were differences in vagal activity at fixed breathing rates in women with CFS. Twelve women with the diagnosis of CFS between the ages of 32 and 59 years volunteered for the study. Healthy women, who were between the ages of 30 and 49, served as controls. Full signal electrocardiograph and respiratory signals were collected during a paced breathing protocol of three fixed breathing rates (8, 12 and 18 breaths/min) performed in the sitting and standing postures. Vagal activity was analyzed by means of heart rate spectral analysis to determine the subject's response to specific breathing rates and postures. Heart rate variability was used as a non-invasive method of measuring the parasympathetic component of the autonomic nervous system. Using this method, although there was significantly less vagal power in the sitting versus the standing postures for both groups, the overall vagal power was significantly lower (p < 0.034) in the CFS group versus healthy controls. Vagal power was also significantly lower (p < 0.01 to p < 0.05) at all breathing rates in both postures except while standing and breathing at 18 breaths/min. Knowledge of the differences in vagal activity for CFS patients may allow stratification for the analysis of other research variables.

Autonomic Nervous System Dysfunction in Adolescents with Postural Orthostatic Tachycardia Syndrome and Chronic Fatigue Syndrome Is Characterized by Attenuated Vagal Baroreflex and Potentiated Sympathetic Vasomotion

“…For the most part, the Valsalva maneuver was normal with an excellent phase II recovery, indicating intact adrenergic vasoconstriction, and patients also had a normal Valsalva ratio and tachycardia ratio, and normal HRV with breathing. This conflicts with the assertion of vagal withdrawal and is at some variance with the literature (19,33) but may implicate altered respiratory modulation of vagal tone.…”

Sympathetic and parasympathetic responses to social stress across adolescence

“…In the present study, this has been handled in two ways. First, tonic RSA was measured during a paced breathing task (e.g., Butler et al, 2006;Hayano et al, 1991;Sisto et al, 1995;Wilhelm, Grossman, & Coyle, 2004) in which each participant breathed at the same relaxed rate in synchrony with a rising and falling bar on a computer screen. Second, analyses that included phasic RSA statistically controlled for actual respiration rates.…”

Neurally mediated hypotension and autonomic dysfunction measured by heart rate variability during head-up tilt testing in children with chronic fatigue syndrome

“…Infectious and immune pathology have often been suspected but have not been conclusively demonstrated as major etiologic factors [24][25][26]. Recent studies of the integrative and regulatory systems are provocative; these have produced interesting information concerning abnormalities in the cardiovascular regulatory areas of the brainstem [27,28], which may be associated with impaired vagal tone in response to synchronized breathing [29], malfunction of central and peripheral nervous system [21], an inability to completely activate skeletal muscle [30], and abbreviated exercise capacity due to early fatigue during treadmill testing [31]. Associated neuroendocrine dysfunction, impaired hypothalamic-pituitary-adrenal interactions [32], and associated neurohumoral findings [33,34] resulting in impaired cardiovascular regulation of blood pressure and cardiac output have been described.…”