Determinant role of short-term heart rate variability in the prediction of mortality in patients with chronic heart failure

The identification of prognostic indexes of sudden death represents a major challenge in the management of patients with chronic heart failure (CHF). In this study the authors present the results of a prospective study on 382 patients aimed at assessing the prognostic value of long- and short-term heart rate variability (HRV) parameters. Survival analysis (Cox model) was performed considering as covariates a set of clinical and functional parameters, including echocardiographic measurements, hemodynamic and exercise testing parameters, blood examinations, 24-hour arrhythmia data and NYHA class, well known to be predictors of total cardiac death. Two final multivariate prognostic models were identified, both containing the short-term low frequency (0.04-0.045 Hz) power during controlled breathing as independent and strongest predictor of sudden death. Model covariates in the two models were respectively the number of premature ventricular contractions per hour and left ventricular ejection fraction.