Electrical remodelling in patients with iatrogenic left bundle branch block

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Left bundle branch block (LBBB) occurs in about a third of transcatheter aortic valve implantation (TAVI) procedures.
• Understanding the electrophysiological consequences of TAVI-induced LBBB is crucial for patient management.

Purpose of the Study:

• To investigate the electrophysiological remodeling in patients who develop LBBB after TAVI.
• To analyze changes in depolarization and repolarization following TAVI-induced LBBB.

Main Methods:

• Retrospective study of 107 patients with pre-existing narrow QRS complex undergoing TAVI.
• Vectorcardiograms reconstructed from 12-lead ECGs (pre-TAVI, acute, and chronic post-TAVI).
• Calculation of QRS and T-wave area to assess depolarization and repolarization.

Main Results:

• TAVI-induced LBBB caused significant acute depolarization and repolarization changes.
• Further repolarization changes were observed with longer-lasting LBBB, showing high inter-patient variability.
• Spatial vector gradient changes indicated shorter action potential duration in later-activated regions.

Conclusions:

• Repolarization changes develop within months after the onset of LBBB post-TAVI.
• The extent of long-term repolarization remodeling is highly variable between individual patients.
• These findings highlight the dynamic electrophysiological impact of TAVI-induced LBBB.