This study aims to investigate the effects of preoperative and postoperative Erector Spinae Plane (ESP) block on the frontal QRS-T angle, a marker of cardiac electrophysiological instability, in patients undergoing laparoscopic cholecystectomy. A total of 120 patients aged 18-65 with ASA I-II status will be randomized into three groups: Control (no ESP), Preoperative ESP, and Postoperative ESP. Electrocardiograms (ECGs) will be obtained preoperatively and one hour postoperatively to assess changes in QRS-T angle and other repolarization parameters. This randomized controlled trial will help clarify the potential cardiac effects of ESP block depending on its timing and may provide insight into optimizing anesthetic safety in surgical patients.