[Resynchronization of left bundle branch block by His bundle pacing : A case series]

Area of Science:

• Cardiology
• Electrophysiology
• Cardiac Conduction System

Background:

• Left bundle branch block (LBBB) is typically associated with significant conduction system disease.
• Conventional understanding suggests LBBB is difficult to correct with His bundle pacing.

Purpose of the Study:

• To investigate the efficacy of His bundle pacing in correcting left bundle branch block.
• To explore potential mechanisms underlying LBBB correction by His bundle pacing.

Main Methods:

• A series of 6 consecutive patients with LBBB underwent distal, nonselective His bundle pacing.
• Electrocardiogram (ECG) criteria were used to assess LBBB morphology and conduction block patterns.

Main Results:

• Distal His bundle pacing resulted in partial or complete correction of LBBB in all patients.
• LBBB morphologies predictive of diffuse or distal conduction block were successfully corrected.
• Pacing may recruit diffusely disturbed conduction fibers and capture distal left bundle fibers.

Conclusions:

• His bundle pacing can effectively correct left bundle branch block, even in cases with diffuse or distal conduction disturbances.
• These findings challenge the conventional understanding of LBBB, suggesting the block may be proximal to the bundle branch division.
• Potential mechanisms include fiber recruitment, distal bundle capture, and concealed conduction.