Neurohumoral activations in congestive heart failure: Correlations with cardiac function, heart rate variability, and baroreceptor sensitivity,

Background The clinical significance of the determination of heart rate variability and baroreceptor sensitivity relating to cardiac function and neurohumoral factors remains to be established. Methods and Results We investigated the relation between conventional clinical variables and frequency domain analysis of heart rate variability and baroreceptor sensitivity in 146 patients with heart failure. Cardiac function including left ventricular ejection fraction, left ventricular dimensions, and left atrial size was different by the plasma atrial natriuretic peptide level but not by the norepinephrine level. The total power and low-frequency power were correlated with plasma norepinephrine, whereas baroreceptor sensitivity was correlated with plasma atrial natriuretic peptide. None of the frequency domain variables and baroreceptor sensitivity was correlated with cardiac function. There was a positive correlation between the low-frequency power and baroreceptor sensitivity. Conclusions Heart rate variability and baroreceptor sensitivity, which reflect autonomic regulation, may be an indicator independent from cardiac function in patients with heart failure. (Am Heart J 1999;137:666-71.)