[Does the etiology of heart failure affect tone response and autonomic reactivity to cardiovascular rehabilitation?]

We examined if the aetiology of heart failure could influence the favourable autonomic response to cardiovascular rehabilitation. We used the autoregressive spectral analysis of RR intervals variability, obtained from 10 minutes of ECG recording: within each autospectrum, we calculated the power of the low (LH) and high frequency (HF) oscillations: their ratio LF/HF is a useful, well accepted index of the sympathovagal balance. In 43 patients with heart failure we evaluated the autonomic tone at rest, during regular breathing (= stimulation of cardiopulmonary receptors, i.e. a parasympathetic challenge) and during active standing (= sympathetic stimulation). The shift in such autonomic response to 3 months of cardiovascular rehabilitation was analyzed separately for patients with ischemic (n = 19) and non-ischemic (n = 24) cardiomyopathy. Before rehabilitation, patients with ischemic cardiomyopathy had a higher sympathetic activity at rest, and a preserved response to parasympathetic stimulation. After rehabilitation, both groups of patients showed an improvement in exercise tolerance and performance, no deterioration in ventricular pump function, and a change in the autonomic profile. Thus, the aetiology of heart failure, despite a different baseline sympathovagal balance, does not influence the favourable clinical and autonomic modulation induced by rehabilitation. Independently from the underlying disease, all clinically stable patients with heart failure can benefit from rehabilitation.