Although left bundle branch area pacing (LBBAP) provides more physiological ventricular activation than conventional pacing techniques, its impact on ventricular repolarization remains unclear. This study investigates the temporal changes of the T wave in patients with bradycardia treated with LBBAP, using vectorcardiographic analysis of 12-lead ECGs. Standard 12-lead ECGs were collected from 23 healthy subjects and 58 patients with bradycardia who underwent LBBAP. ECGs were recorded at baseline for the two cohorts and at three additional time points after LBBAP for the bradycardia group. The principal direction of the T wave was obtained from vectorcardiographic analysis and classified into 4 quadrants (qx). In healthy controls, all T wave vectors were located in q1. In patients with bradycardia and narrow QRS, 80% of the T wave vectors lied in q1 at baseline. A reduction in the number of T wave vectors belonging to q1 was observed immediately after LBBAP (45%), followed by a significant increase in this number at 24 hours (75%) and again at one year post-implantation (80%) (p<0.05). Qualitatively similar results were obtained for patients with wide QRS at baseline. These findings suggest that, although LBBAP transiently alters the direction of ventricular repolarization, the T wave vector progressively realigns to a physiological pattern over time.