Right Bundle Branch Conduction in Left Bundle Branch Area Pacing
Takefumi Fujito1, Kento Erata1, Naoto Noumura2
1Department of Cardiovascular-Kidney-Metabolic Medicine Sapporo Medical University School of Medicine Sapporo Japan.
Journal of Arrhythmia
|April 9, 2026
Insights
Left bundle branch area pacing can activate the right bundle branch, causing right ventricular activation. This challenges standard electrocardiogram (ECG) methods for confirming left bundle branch capture.
Area of Science:
- Cardiology
- Electrophysiology
- Cardiac Pacing
Background:
- Left bundle branch block (LBBB) affects cardiac conduction.
- Left bundle branch area pacing (LBBAP) is an advanced pacing technique.
- Understanding LBBAP's electrical spread is crucial for effective pacing.
Purpose of the Study:
- To investigate the electrical activation patterns during LBBAP.
- To determine if LBBAP can influence right ventricular activation.
- To evaluate the implications for electrocardiogram (ECG) interpretation.
Main Methods:
- Utilized electrophysiological study.
- Analyzed activation sequences during LBBAP.
- Correlated pacing parameters with ECG findings.
Main Results:
- Electrical activation from LBBAP was observed to penetrate the right bundle branch.
- This penetration led to significant right ventricular activation.
- Conventional ECG criteria for LBB capture may be confounded by this phenomenon.
Conclusions:
- LBBAP can result in simultaneous or near-simultaneous activation of both ventricles.
- Standard ECG indicators for LBB capture require reassessment in cases of dual activation.
- Further research is needed to refine ECG interpretation for LBBAP.
Abstract:
The electrical activation during left bundle branch area pacing can penetrate into the right bundle branch, resulting in right ventricular activation. These findings suggest that conventional ECG indicators for confirming left bundle branch capture should be reconsidered when the right bundle branch contributes to right ventricular activation.
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