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.