Early changes in depolarization and repolarization after catheter ablation of ventricular tachycardia in ischemic cardiomyopathy.

INTRODUCTION: The development of ventricular tachycardia (VT) has been shown to be associated with depolarization-repolarization parameters. However, the effect of radiofrequency ablation (RFA) applied for VT on depolarization-repolarization parameters remains unknown. AIM: This study aimed to investigate changes in measurable depolarization-repolarization parameters following successful RFA in patients with ischemia-induced VT. MATERIAL AND METHODS: Ninety-six patients with ischemic cardiomyopathy who underwent successful RFA for VT between 2018 and 2025 were included. Twelve-lead electrocardiograms (ECGs) were recorded before and after (72 h) the RFA. From both ECGs, PR and QRS durations, QT, corrected QT interval (QTc), Tp-Te intervals, Tp-Te/QT ratio, and QRS-T angle were measured. In addition, left ventricular ejection fraction (LVEF) was measured before and after RFA. Early changes in ECG parameters and LVEF due to RFA were evaluated. RESULTS: The mean age of the study population was 65.8 ±10.6 years, and 83% of the patients were male. Analysis of ECG parameters showed significant differences before and after VT ablation in QT, QTc, Tp-Te intervals, Tp-Te/QT ratio, and QRS-T angle (p < 0.001 for all). QT interval (426 ±33 vs. 409 ±31 ms), QTc interval (441 ±18 vs. 424 ±17 ms), Tp-Te interval (89 ±16 vs. 80 ±16 ms), Tp-Te/QT ratio (0.21 ±0.04 vs. 0.20 ±0.04), and QRS-T angle (93 ±51°; vs. 72 ±45°;) were all reduced after RFA. There was no significant change in LVEF before and after RFA (33.6 ±9.8 vs.34.1 ±8.5, Z = -1.356, p = 0.195). CONCLUSIONS: Our findings demonstrated that successful RFA therapy in patients with ischemia-induced VT has favorable early effects on ventricular depolarization-repolarization parameters. This information provides a novel and important contribution to the literature on VT ablation.