Heart rate variability index in congestive heart failure: Relation to clinical variables and prognosis

Abstract

Aim. To evaluate the clinical and prognostic value of the heart rate variability index in patients with congestive heart failure. Methods. Sixty-four patients with chronic congestive heart failure and sinus rhythm underwent clinical assessment, 24-h ambulatory electrocardiography and echocardiography. Patients were followed for 6 to 30 months. Cardiac death or heart transplantation constituted the primary end-point of the study. Results. The heart rate variability index was related to left ventricular ejection fraction (r = 0.29, P = 0.02) and New York Heart Association class (P = 0.01). Patients with a restrictive left ventricular filling pattern had a lower heart rate variability index compared to patients with a non-restrictive pattern (26 ± 11 vs 33 ± 9 units, P = 0.01). Patients who died (n = 4) or underwent heart transplantation (n = 4) had a lower heart rate variability index compared to survivors (21 ± 10 vs 33 ± 9 units, P < 0.0001). In multivariate survival analysis, a reduced heart rate variability index was related to survival independent of parameters of left ventricular function. Conclusion. The heart rate variability index provides independent information on clinical status and prognosis in patients with chronic congestive heart failure.