The role of the autonomic nervous system in congestive heart failure

Altered sympathovagal balance could be a substrate for malignant ventricular arrhythmias in congestive heart failure. The aim of this study is to assess neuroautonomic function by power spectral analysis in patients with congestive heart failure and the effects of treatment with carvedilol in these patients. We compared the LF/HF ratio of all patients at baseline and after sympathetic stress (tilt). In group I, we considered 10 patients with congestive heart failure and 10 controls mean aged 60 years, while in group II were 10 patients with heart failure 70 years old and normal subjects age-matched. In group I, al rest the subjects with congestive heart failure had a significantly greater LF/HF (p<0.001) than controls. In contrast, it increased significantly after tilt in control subjects. In group II, at rest LF/HF did not differ between patients with congestive heart failure and normal subjects, while after tilt it resulted higher in controls (p<0.05). After a month of 25 mg daily of carvedilol administration in patients with heart failure in group I, both at rest and after tilt, LF/HF was significantly greater in patients in wash-out than treated (p<0.001). In group II there weren't significant differences both at rest and after tilt. Tt lis study showed increase of sympathetic activity in patients with congestive heart failure mean aged 60 years, less evident in patients aged 70 years. Carvedilol can exert beneficial myocardial effects in these patients, because reduces morbidity and mortality and can favorably influence the course of disease and prolong survival.