Immediate changes in depolarization and repolarization after left bundle branch area pacing and atrioventricular
Mert Doğan1, Uğur Canpolat1, Cem Çöteli1
1Hacettepe University, Faculty of Medicine, Department of Cardiology, Ankara, Turkey.
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.
Related Concept Videos
Electrophysiology of Normal Cardiac Rhythm
Cardiac Action Potential
The cardiac action potential process involves a series of phases characterized by the movement of ions across the cardiac cell membranes, leading to the depolarization and repolarization of the cardiac myocytes.
Ionic Basis of Cardiac Action Potentials
Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers
Disturbances in Heart Rhythm
Arrhythmias are categorized by their speed, rhythm, and origin. A slow...
Conduction System of the Heart
The pacemaker cells are located in two primary nodes: the sinoatrial (SA) node and the atrioventricular (AV) node. The SA node pacemaker cells can autonomously depolarize, triggering an action potential that leads to the...
Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...


