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Updated: Jun 23, 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

Toward understanding response to cardiac resynchronization therapy: left ventricular dyssynchrony is only one of

Chirine Parsai1, Bart Bijnens, George Ross Sutherland

  • 1Department of Cardiology, St George's Hospital, Blackshaw Road, SW17 0QT London, UK. chirineparsai@hotmail.com

European Heart Journal
|November 14, 2008
PubMed

Insights

Cardiac resynchronization therapy (CRT) response depends on multiple factors, not just left ventricular dyssynchrony. Identifying and correcting these correctable mechanisms improves patient outcomes.

Area of Science:

  • Cardiology
  • Medical Imaging
  • Biomedical Engineering

Background:

  • Current echocardiographic methods primarily assess left ventricular dyssynchrony (LV DYS) as a sole predictor for cardiac resynchronization therapy (CRT) response.
  • This study challenges that notion, hypothesizing that multiple correctable factors dictate CRT efficacy.

Purpose of the Study:

  • To investigate whether multiple independent mechanisms, beyond LV DYS, predict response to CRT.
  • To identify specific pathological mechanisms influencing CRT outcomes.

Main Methods:

  • 161 patients undergoing CRT were evaluated pre- and post-therapy using echocardiography.
  • Response was defined by NYHA Class reduction or LV reverse remodeling.
  • Four distinct pathological mechanisms were identified and analyzed for their impact on CRT response.

Main Results:

  • Left ventricular dyssynchrony with septal flash (LV DYS-SF) was observed in 54% of patients, with 100% reverse remodeling upon SF elimination.
  • Other identified mechanisms included short-AV delay (13%), long-AV delay (10%), and exaggerated LV-RV interaction (9%), each showing varying degrees of response.
  • 14% of patients had none of these correctable mechanisms and did not respond to CRT.

Conclusions:

  • CRT response is multifactorial, with LV DYS being only one component.
  • Echocardiographic assessments focusing solely on long-axis DYS measurements underestimate treatment response by failing to identify up to 40% of responders.
Abstract

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