Autonomic nervous system and neuro-humoral correlation in chronic heart failure patients

Purpose: It is well known the neuro-humoral excitation associated with heart failure and its role in the disease prognosis. Several authors showed that analysis of heart rate variability (HRV) is a valid technique to asses the sympathovagal balance of the heart. It is still unknown the relationship between neuronal derangment and autonomic system status in chronic heart failure (CHF) patients. Aim of our study was to evaluate the hypothetical correlation between the unbalance of autonomic nervous system and the neuro-humoral situation in patients with CHF. Methods: We assessed by power spectral analysis the autonomic dysfunction in 55 patients with stable CHF (mean age 60±9). The mean EF was 25.4±6.9 and the NHYA class was 28 in II, 22 in III and 5 in IV. HRV was evaluated, in both the time and the frequency domain, through the autoregressive power spectral analysis of 600 beat ECG samples while the subjects were quite recumbent (BS1); controlled breathing (15 acts/min) (RSC); in passive orthostatism after tilting (80°) (TLT) and again basal condition (BS2). Neuro-humoral pattern (adrenaline, noradrenaline, atrial natriuretic peptide (ANP), aldosteron, plasmatic renin-angiotensin) were assessed in each patients analysing venous blood samples. Results: The patients showed two different patters of HRV with regard to total power in LF band (0.03-0.15 Hz): 13 pts did not showed power in this band, whereas 42 had increased LF power. We failed to show any significant correlation between the two groups of pts and frequency and time domain measured parameters. All our pts snowed a increase serum level for each evaluated hormone, but we found a significant inverse correlation, at rest, only between ANP and variance coefficient (CV) (p