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

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Dispersion of repolarization increases with cardiac resynchronization therapy and is associated with left ventricular

Mark K Elliott1, Marina Strocchi2, Vishal S Mehta1

  • 1School of Biomedical Engineering and Imaging Sciences, King's College London, UK; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, UK.

Journal of Electrocardiology
|April 25, 2022
PubMed

Insights

Cardiac resynchronization therapy (CRT) increases left ventricular (LV) repolarization dispersion over 6 months, particularly in patients with significant LV remodeling. This change in dispersion is linked to reverse remodeling and may influence arrhythmia risk.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Medical Imaging

Background:

  • Cardiac resynchronization therapy (CRT) is used to treat heart failure with electrical dyssynchrony.
  • While CRT improves ventricular activation, its impact on repolarization dispersion remains unclear.
  • Left ventricular (LV) remodeling is a key factor in heart failure progression.

Purpose of the Study:

  • To investigate the effect of CRT on repolarization dispersion in the LV.
  • To assess the influence of LV remodeling on repolarization changes after CRT.
  • To utilize electrocardiographic imaging (ECGi) for detailed repolarization mapping.

Main Methods:

  • 11 heart failure patients with electrical dyssynchrony underwent ECGi before and 6 months after CRT.
  • Epicardial electrograms were reconstructed to map activation and repolarization times.
  • Measures of repolarization dispersion, including heart rate-corrected activation recovery intervals (cARI), were calculated.

Main Results:

  • LV cARI dispersion significantly increased at 6 months post-CRT compared to baseline (P=0.03).
  • No significant changes in mean LV cARI or repolarization time metrics were observed.
  • Significant LV remodeling independently predicted increased LV cARI dispersion (P=0.04).

Conclusions:

  • CRT leads to increased LV cARI dispersion, with the effect becoming apparent by 6 months.
  • The observed increase in dispersion appears dependent on LV reverse remodeling.
  • These findings suggest a link between CRT-induced repolarization changes, reverse remodeling, and potential arrhythmia risk.
Abstract

Keywords:
Cardiac memoryCardiac resynchronization therapyElectrical remodelingElectrocardiographic imagingRepolarizationVentricular arrhythmias

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