Effect of beta-blockade on heart rate variability in decompensated heart failure

Int J Cardiol. 2001 Jun;79(1):31-9. doi: 10.1016/s0167-5273(01)00401-6.

Abstract

Background: One of the putative mechanisms for the salutary effects of beta-blockers in patients with congestive heart failure is their ability to improve autonomic dysfunction. However, patients with profound neurohumoral abnormalities derive little survival benefit from beta-blockers. The purpose of the current study was to evaluate the effect of beta-blockers on heart rate variability in decompensated heart failure.

Methods: Time and frequency domain heart rate variability indices were obtained from 24-h Holter recordings and compared to assess the role of beta-blockade in 199 patients (mean age 60+/-14 years [range 21 to 87]) with decompensated heart failure (New York Heart Association functional class III [66%] and IV [34%]).

Results: All heart rate variability indices were markedly suppressed but were substantially higher in patients who were on beta-blockers. Time domain measures of parasympathetic cardiac activity, the percentage of RR intervals with >50 ms variation (4.9+/-0.6 vs. 7.7+/-1.2%, P=0.006) and the square root of mean squared differences of successive RR intervals (22.7+/-2.0 vs. 31.6+/-4.1 ms, P=0.004), were higher in the beta-blocker group. Spectral analysis revealed that the total power and the ultra low frequency power were significantly higher in patients on beta-blockers (82% and 59%, respectively). The high frequency power, a spectral index of parasympathetic modulation, was 41% higher in the beta-blocker group (121+/-25 vs. 171+/-27 ms(2), P=0.02). Multiple linear regression, adjusted for clinical parameters and drug therapies, revealed a strong positive relationship between beta-blockade and higher values of time and frequency domain measures. The mean number of ventricular tachycardia episodes were significantly lower in patients on beta-blocker therapy (3.6+/-1.5 vs. 19.0+/-5.3, P=0.04).

Conclusions: beta-blockers improve the impaired cardiac autonomic regulation during high sympathetic stress of decompensated heart failure.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic beta-Antagonists / pharmacology*
  • Adrenergic beta-Antagonists / therapeutic use*
  • Adult
  • Aged
  • Aged, 80 and over
  • Electrocardiography, Ambulatory
  • Female
  • Heart / drug effects
  • Heart / physiopathology
  • Heart Failure / drug therapy*
  • Heart Failure / physiopathology
  • Heart Rate / drug effects*
  • Heart Rate / physiology
  • Humans
  • Male
  • Middle Aged

Substances

  • Adrenergic beta-Antagonists