Evaluation of changes in the frontal QRS-T angle in patients with ventricular extrasystole, before and after ventricular extrasystole radiofrequency catheter ablation using complex mapping

Ventricular extrasystole is one of the most common arrythmias in general population, and may cause cardiomyopathy in some individuals. Although this condition, called ventricular extrasystole-related cardiomyopathy, does not develop in every individual; current literature information on which individuals are susceptible to develop this condition is limited. Thanks to advancing technology in recent years, routine clinical use of ablating arrhythmogenic foci of the ventricular extrasystole with complex mapping systems and radiofrequency catheters demonstrated that this procedure can reverse the development of cardiomyopathy. Thus, this treatment method has been included in current guidelines. Frontal QRS-T angle is a marker of cardiac repolarization heterogeneity. Studies have found that impaired frontal QRS-T angle is associated with arrhythmias and sudden cardiac death. To our knowledge, there is no study in the current literature on the effects of the transcatheter radiofrequency ablation of ventricular extrasystoles on the frontal QRS-T angle. For this reason, we aimed to investigate the frontal QRS-T angle changes that occur after ventricular extrasystole ablation in our study.In total number of 48 patients composed of 24 male and 24 female patients who underwent ventricular extrasystole radiofrequency catheter ablation with the three-dimensional complex mapping method in the centres of Afyonkarahisar Health Sciences University Research and Education Hospital, Suleyman Demirel University Research and Education Hospital, and Eskisehir City Hospital were included in our study by retrospectively scanning hospital data. Patients with atrial fibrillation, left or right bundle branch block, or pacemaker rhythm were not included in the study. Hospital data of all patients were scanned and levels of complete blood count, serum electrolytes, kidney function tests, fasting lipid panels, and reports of 24-hour rhythm holter records, transthoracic echocardiography and ventricular extrasystole ablation procedures were obtained from the hospital systems. Standard 12-lead electrocardiograms of all patients recorded before and after ablation, were scanned from the system. Then, from these electrocardiograms, frontal QRS-T angles during basal sinus rhythm were calculated and frontal QRS-T angles before and after the procedure were recorded. All data obtained were evaluated statistically.The frontal QRS-T angle was found to be abnormal before ablation in 6 of the 48 patients, and normal in the remaining 42 patients. After the ablation, the frontal QRS-T angle returned to normal limits in 6 of the 6 patients with abnormal frontal QRS-T angles, and the frontal QRS-T angles of 42 patients with normal frontal QRS-T angles before the ablation continued to remain within normal limits after the ablation. In statistical analysis, comparison of patients with abnormal frontal QRS-T angle before ablation with patients with pre-procedural normal frontal QRS-T angle, showed that the increased number of daily ventricular extrasystoles detected in 24-hour rhythm holter was correlated with the development of abnormal frontal QRS-T angle. No statistically significant correlation was detected in the analyzes of other findings.It was determined that the application of transcatheter radiofrequency ablation of ventricular extrasystoles with the three-dimensional mapping method did not cause deterioration in the frontal QRS-T angle in patients with normal frontal QRS-T angle. In patients with abnormal frontal QRS-T angle, it was determined that the frontal QRS-T angle ix returned to normal limits after ventricular extrasystole ablation. It was determined that the deterioration in the frontal QRS-T angle evaluated before the ablation procedure was correlated with the daily number of ventricular extrasystoles.We believe that prospective studies with a larger patient group are needed to investigate how the frontal QRS-T angle, which has been shown to be predictive of malignant arrhythmia development and sudden cardiac death, is affected by ventricular extrasystoles and the effects of ventricular extrasystole ablation on the development of cardiomyopathy in these patients. Key words: Arrhythmia InducedCardiomyopathy, Frontal QRS-T Angle, Ventricular Extrasystole.