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Updated: May 23, 2026
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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
Comparison of quick optimization of interventricular delay between simple methods: intracardiac electrogram and
Chien-Ming Cheng1, Jin-Long Huang, Tsu-Juey Wu
1Division of Cardiology, Department of Medicine, Fong Yuan Hospital, Taiwan.
Summary
Optimizing interventricular delay for cardiac resynchronization therapy (CRT) is faster with intracardiac electrogram (IEGM) or surface electrocardiogram (ECG) guidance. Both methods equally improve key patient parameters, enhancing CRT effectiveness.
Area of Science:
- Cardiology
- Medical Devices
- Electrophysiology
Background:
- Conventional methods for optimizing interventricular (VV) delay in cardiac resynchronization therapy (CRT) are time-consuming.
- Efficient optimization of VV delay is crucial for successful CRT outcomes.
Purpose of the Study:
- To compare the speed and effectiveness of intracardiac electrogram (IEGM)-guided versus surface electrocardiogram (ECG)-guided VV delay optimization for CRT.
- To evaluate the impact of these optimization methods on various hemodynamic and echocardiographic parameters.
Main Methods:
- Fifty-one heart failure patients undergoing CRT implantation were included.
- VV delay optimization was performed using either IEGM or surface ECG guidance after atrioventricular optimization.
- Aortic velocity time integral (AVTI) served as the primary reference, with real-time three-dimensional echocardiography assessing parameters like QRS width, systolic dyssynchrony index (SDI), left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), and left ventricular end-systolic volume (LVESV).
Main Results:
- Both IEGM-guided and surface ECG-guided VV optimization equally improved AVTI.
- Significant improvements were observed in QRS width, SDI, LVEF, LVEDV, and LVESV with both optimization methods.
- Immediate improvement in acute LVEF was independently associated with favorable outcomes (odds ratio 1.23, P = 0.02).
Conclusions:
- IEGM-guided and surface ECG-guided methods provide comparable improvements in AVTI, QRS width, SDI, LVEF, LVEDV, and LVESV following CRT.
- Both techniques offer effective strategies for VV delay optimization in CRT patients.
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