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Related Experiment Video

Updated: Dec 17, 2025

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

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

Interrelationships between interventricular electrical delays in cardiac resynchronization therapy.

Ghassan Moubarak¹, Frédéric A Sebag², Pierre Socie³

¹Department of Electrophysiology and Pacing, Centre Médico-Chirurgical Ambroise Paré, Neuilly-sur-Seine, France.

Journal of Cardiovascular Electrophysiology

|June 21, 2020

Summary

This summary is machine-generated.

Understanding interventricular delays in cardiac resynchronization therapy is key. Pacing the left ventricle (LV) at sites of electrical delay improves outcomes, but optimal LV vector selection requires careful consideration of patient-specific delays.

Keywords:

activation propagation cardiac resynchronization therapy correlation interventricular delays latest-activated electrode local electrical delay

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Bidirectional Electrical and Optoelectronic Interfaces in Healthy and Ischemic Ex Vivo Rat Hearts

Published on: July 18, 2025

Area of Science:

Cardiology
Electrophysiology
Medical Devices

Background:

Cardiac resynchronization therapy (CRT) improves outcomes when pacing the left ventricle (LV) at sites of electrical delay.
Interventricular delays are crucial for optimizing CRT lead placement and patient response.

Purpose of the Study:

To characterize the interrelationships between intrinsic, right-ventricular (RV)-paced, and LV-paced interventricular delays.
To investigate the implications of these delays for selecting the optimal LV pacing vector.

Main Methods:

Measured interventricular electrical timings (QLV, RVs-LVs, RVp-LVs, LVp-RVs) in 32 patients undergoing CRT implantation.
Analyzed correlations between different pacing rhythms and electrode activation sites.
Evaluated concordance of latest-activated electrodes and its relation to echocardiographic response.

Main Results:

Intrinsic and RV-paced interventricular delays showed significant correlations (R² values ranging from 0.27 to 0.72).
However, substantial patient heterogeneity was observed in delay patterns and latest-activated electrode locations.
Dissimilar latest electrodes between intrinsic and RV-paced rhythms occurred in 47% of patients, impacting biventricular-paced QRS duration.

Conclusions:

Intrinsic and RV-paced interventricular electrical delays are correlated but exhibit significant patient variability.
The latest-activated electrode can differ between intrinsic and RV-paced rhythms, highlighting potential challenges in optimal LV vector selection.
These findings underscore the importance of personalized LV lead placement strategies in CRT.