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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
Reverse electrical remodeling by cardiac resynchronization therapy: prevalence and clinical impact
Frederic A Sebag1, Raphael P Martins, Pascal Defaye
1INSERM U642, Rennes, France Université de Rennes 1, LTSI, Rennes, France.
Journal of Cardiovascular Electrophysiology
|June 16, 2012
Summary
Cardiac resynchronization therapy (CRT) shortens intrinsic QRS duration, improving heart function. A reduction of 20 ms or more in QRS duration predicts better clinical and echocardiographic response in heart failure patients.
Area of Science:
- Cardiology
- Electrophysiology
- Heart Failure Management
Background:
- Cardiac resynchronization therapy (CRT) enhances left ventricular ejection fraction (LVEF) in heart failure patients with LV systolic dysfunction and wide QRS.
- The impact of CRT-induced electrical remodeling on clinical outcomes remains under investigation.
Purpose of the Study:
- To determine if chronic CRT significantly shortens intrinsic QRS (iQRS) duration.
- To assess the correlation between native conduction system changes and CRT response (clinical/echocardiographic).
- To identify predictors of iQRS width shortening following CRT.
Main Methods:
- Prospective study of 85 left bundle-branch block patients receiving CRT.
- Assessment of NYHA class, iQRS duration, LVEF, and LV volumes pre- and 1-year post-CRT.
- Defined responders based on clinical improvement, LVEF increase, LVESV decrease, or iQRS duration reduction (≥20 ms).
Main Results:
- Mean iQRS duration decreased from 168.0 ms to 149.6 ms (P < 0.0001).
- Electrocardiographic response (iQRS reduction ≥20 ms) occurred in 51% of patients and correlated with better clinical and echocardiographic outcomes.
- Younger age, male gender, and wider baseline QRS predicted electrocardiographic response.
Conclusions:
- CRT effectively reduces intrinsic QRS duration.
- A ≥20 ms reduction in iQRS duration is linked to improved clinical and echocardiographic response to CRT.
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