Immediate changes in depolarization and repolarization after left bundle branch area pacing and atrioventricular nodal ablation

Abstract

Background

Malignant arrhythmia due to ventricular depolarization and repolarization alterations after atrioventricular node (AVN) ablation is a known clinical entity. Here, we aimed to demonstrate the ventricular depolarization and repolarization changes in patients who underwent left bundle branch area pacing (LBBaP) and AVN ablation.

Methods

This is a single-center, retrospective preliminary study (n = 10). All patients underwent single-chamber pacemaker implantation with LBBaP before the AVN ablation procedure. Electrocardiographic (ECG) parameters [QRS duration (QRSd), QTc (Fridericia formula), Tp-e, and JT interval] were measured and analyzed before and after the procedure.

Results

The mean age of the study population was 67.1 ± 8.88 years, and 70 % of the patients were female. 60 % of the patients had AF, and 40 % of them had atrial tachycardia during the procedures. Eight patients had undergone more than two catheter ablations before the procedure. The QT interval (263.47 ± 26.79 vs. 416.14 ± 36.31 msec) and QRSd (93.3 ± 7.3 vs. 122.32 ± 21.16 msec) were prolonged when the patient's ECG parameters were analyzed. Still, the Tp-Te interval (75.57 ± 18.62 vs. 80.93 ± 17.35 msec) did not change, and the QTc (Fridericia formula) interval (425 ± 29.82 vs. 461.70 ± 35.33 msec) did not show a significant difference.

Conclusion

Malignant arrhythmia may occur due to ventricular depolarization and repolarization changes after the AVN ablation procedure. This study showed no significant change in Tp-e and QTc durations previously defined for malignant arrhythmia development. At the same time, JT time, which indicates ventricular repolarization duration, did not show a significant difference. LBBaP is more physiological and safer for patients planning to undergo AVN ablation.