Autonomic dysfunction in patients with fibromyalgia: Application of power spectral analysis of heart rate variability

Objectives: To assess the interaction between the sympathetic and parasympa thetic systems in patients with fibromyalgia syndrome (FM), using power spe ctrum analysis (PSA) of heart rate variability (HRV). In addition, we explo red the association between HRV, measures of tenderness, FM symptoms, physi cal function, psychological well being and quality of life. Methods: We studied 22 women with FM and 22 age-matched healthy women. Twen ty-minute electrocardiogram recordings were obtained in a supine position d uring complete rest. Spectral analysis of R-R intervals was done by the fas t-Fourier transform algorithm. Results: Heart rate was significantly higher in FM patients compared with c ontrols (P<.006). FM patients had significantly lower HRV compared with con trols (P=.001), and higher low-frequency (LF) and lower high-frequency (HF) components of PSA than controls (P<.001). Quality of life, physical functi on, anxiety, depression, and perceived stress were moderately to highly cor related with LF HF (in normalized units), and LF/HF. No association was obs erved between HRV parameters and measures of tenderness and FM symptoms. Conclusions: The basal autonomic state of patients with FM is characterized by increased sympathetic and decreased parasympathetic tones. Autonomic dy sregulation may have implications regarding the symptomatology, physical an d psychological aspects of health status. Semin Arthritis Rheum 29:277-227. Copyright (C) 2000 by W.B. Saunders Company.