Right Ventricular vs Left Bundle Branch Pacing-Induced Changes in ECG Depolarization and Repolarization

Patients suffering from bradycardia are indicated for pacemaker implantation. Right ventricular pacing (RVP) has been conventionally used for this purpose, but it can increase the risk of atrial fibrillation and heart failure. Left bundle branch area pacing (LBBAP) has been proposed as a new physiological pacing technique. The aim of this study was to compare changes induced by RVP and LBBAP in the ECG. 10-minute 12-lead ECG recordings were acquired at baseline and after pacemaker implantation from 83 patients (31 RVP, 52 LBBAP). Median beats were calculated for each patient at baseline and post-implantation states. ECG markers including QRS duration (dQRS) and area (aQRS) and heart rate-corrected QT (QTc) and Tpeak-to-Tend (Tpec) intervals were measured. dQRS and aQRS decreased significantly at post-implantation with respect to baseline, both being significantly lower for LBBAP than RVP after pacemaker implantation. QTc was significantly reduced at post-implantation for both pacing techniques with no differences between them. Tpec did not change either between states or techniques. In conclusion, LBBAP led to more synchronized ventricular depolarization, supporting potentially improved clinical outcomes with LBBAP as compared to RVP for anti-bradycardia therapy.