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Updated: May 12, 2026

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

Dyssynchrony and the risk of ventricular arrhythmias

Valentina Kutyifa1, Anne-Catherine Pouleur, Dorit Knappe

  • 1University of Rochester Medical Center, Rochester, New York, USA. valentina.kutyifa@heart.rochester.edu

JACC. Cardiovascular Imaging
|April 13, 2013
PubMed

Insights

Improving left ventricular (LV) dyssynchrony with cardiac resynchronization therapy (CRT) significantly reduces ventricular arrhythmias in heart failure patients with left bundle branch block (LBBB). Baseline LV dyssynchrony did not predict these events in LBBB or non-LBBB patients.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Heart Failure Research

Background:

  • Intraventricular mechanical dyssynchrony may contribute to ventricular arrhythmias in heart failure patients.
  • Previous studies have not extensively evaluated dyssynchrony in large cohorts of implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy with defibrillator (CRT-D) patients.

Purpose of the Study:

  • To investigate the association between left ventricular (LV) dyssynchrony and the risk of ventricular tachycardia (VT) or ventricular fibrillation (VF).
  • To evaluate the impact of CRT on LV dyssynchrony and subsequent arrhythmia risk in patients within the MADIT-CRT trial.

Main Methods:

  • LV dyssynchrony assessed using speckle-tracking echocardiography (standard deviation of time to peak systolic strain in 12 LV segments) at baseline and 12 months.
  • Primary endpoint was the first occurrence of VT/VF/death or VT/VF.
  • Study population included 764 patients with left bundle branch block (LBBB) and 312 without LBBB, treated with either ICD or CRT-D.

Main Results:

  • Baseline LV dyssynchrony did not predict VT/VF/death or VT/VF in either LBBB or non-LBBB patients.
  • In CRT-D patients with LBBB, improved LV dyssynchrony over one year correlated with significantly lower rates of VT/VF/death and VT/VF.
  • A 15% decrease in LV dyssynchrony in LBBB patients was associated with reduced risk of VT/VF/death and VT/VF compared to ICD patients.

Conclusions:

  • Baseline LV dyssynchrony is not a predictor of ventricular arrhythmias in mild heart failure patients, irrespective of LBBB status.
  • Cardiac resynchronization therapy-induced improvement in LV dyssynchrony significantly reduces ventricular arrhythmias, particularly in patients with LBBB.
Abstract

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