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Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
12:45

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing

Published on: December 11, 2017

Cardiac resynchronization therapy in patients with right bundle branch block: analysis of pooled data from the

Cesar A Egoavil1, Reginald T Ho, Arnold J Greenspon

  • 1Thomas Jefferson University and Jefferson Heart Institute, Philadelphia, Pennsylvania 19107, USA.

Heart Rhythm
|June 1, 2005
PubMed

Insights

Cardiac resynchronization therapy (CRT) showed limited benefits for patients with right bundle branch block (RBBB), with only New York Heart Association class improving. Further studies are needed to confirm if CRT benefits RBBB patients.

Area of Science:

  • Cardiology
  • Electrophysiology

Background:

  • Limited inclusion of right bundle branch block (RBBB) patients in cardiac resynchronization therapy (CRT) clinical trials.
  • RBBB is a specific conduction abnormality affecting ventricular depolarization.

Purpose of the Study:

  • To assess the outcomes of patients with RBBB who received CRT.
  • To pool data from two randomized controlled trials (MIRACLE and Contak CD) for RBBB patient analysis.

Main Methods:

  • Identified 61 patients with RBBB, randomized to CRT (34) or control (27) groups.
  • Analyzed baseline demographics, QRS duration, and various outcome variables at 3 and 6 months.

Main Results:

  • No significant differences in baseline demographics between CRT and control groups.
  • CRT patients showed improvements in NYHA class, with trends in walk distance and quality of life.
  • Control group also improved in NYHA class, suggesting a potential placebo effect for objective measures.

Conclusions:

  • Patients with RBBB as the qualifying wide QRS did not derive significant benefit from CRT, except for NYHA class.
  • Current analysis does not support CRT use in RBBB patients, pending larger cohort studies.
  • Observed improvements in control group suggest a placebo effect, complicating interpretation of CRT benefits in RBBB.
Abstract

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