Sympathetic Overactivity in Subjects Complaining of Unexplained Fatigue

摘要: 1. Theoretical and practical considerations suggest that in subjects complaining of fatigue, the absence evident organ dysfunction, an alteration autonomic nervous system might be present as a functional correlate. 2. Autoregressive spectral analysis R-R interval variability from surface ECG, was used healthy control (n = 24, age 45 +/- 4 years) unexplained fatigue 53, 46 9 to obtain quantitative indices state sympathovagal balance, both at rest during mental stimulus (mental arithmetic), capable enhancing sympathetic drive. Sympathetic vagal modulations were inferred normalized powers low frequency high components respectively. 3. We observed patients, rest, prevailing component (patients 73 11, 51 10 units, P < 0.05). The responsiveness arithmetic reduced patients compared with controls. Systolic blood pressure did not differ. This suggested selective imbalance sinoatrial node, characterized by predominance well withdrawal, rest. 4. possibility discriminating on basis simple non-invasive markers provide better understanding mechanisms, clinical evolution outcome conditions such chronic syndrome, which lack ordinary evidence disease, but comprise, physiopathological correlate, control.