Detailed Electrode Catheter Positioning is Important for the Ablation of Outflow Tract Origin Ventricular Arrhythmias

Background and Objectives: Electroanatomical mapping using a three-dimensional (3D) system has high accuracy and improves the results of the ablation of outflow tract (OT) premature ventricular contraction (PVC) or ventricular tachycardia (VT) but imposes a considerable economic burden. Here, we compared detailed diagnostic catheterization and 3D mapping system for the ablation of OT PVC/VT. Materials and Methods: Between June 2012 and February 2017, patients with symptomatic OT PVC/VT underwent radiofrequency ablation. Group 1 underwent detailed diagnostic catheterization (using circular and linear multielectrodes) without a 3D mapping system, while group 2 underwent diagnostic catheterization using a conventional 3D mapping system. Procedural success of PVC reduction, remaining symptoms, need for post-operative medications, and procedural time were evaluated. Results: Ninety-eight OT PVC/VT cases were consecutively enrolled. The mean follow-up period was 17.714.5 months. Neither acute success rate (95% vs. 82%, p=0.06) nor a PVC reduction > 80% (84% vs. 87%, p=0.74) differed significantly between the two groups. The recurrence rates of PVC-related symptoms were similar (12% vs. 7%, p=0.06) between the groups, but the medication requirement for symptomatic PVC differed (12% vs. 29%, p<0.01). The total procedure time of group 1 was shorter than that of group 2 (13242 min vs. 15747 min, p=0.01) and fluoroscopy time (2415 min vs. 3822 min, p<0.01) and ablation time (528538 sec vs. 899598 sec, p<0.01) were also significantly shortened. Conclusion: Detailed electrode catheter positioning is a safe and cost-effective method for the ablation of OT PVC/VT.