Outflow tract ventricular arrhythmia originating from the aortic cusps: our approach for challenging ablation.

Background: Ablation of outflow flow ventricular arrhythmia (VA) originating from aortic cusps can be challenging. The aim of this study was to describe our approach for this ablation.
Methods: All patients with outflow VA suspected to originate from aortic cusps according to ECG or after failed ablation from right ventricular outflow tract (RVOT) underwent cardiac CT and radiofrequency ablation. CT image of aortic cusps and coronary arteries was integrated into electroanatomic mapping system by point (left main ostium)-based registration. Ablation was performed at the earliest activation site.
Results: Ten patients were included in this case cohort. The ablation catheter was easily maneuvered above and below the aortic valve after registration. Two patients who had previous failed ablation of RVOT focus had successful ablation at right coronary cusp (RCC) and at left coronary cusp (LCC). A patient who had previous failed ablations of RVOT and LCC focuses had successful ablation at RCC-LCC junction. A patient who had previous failed ablation at LCC had successful ablation at RCC-LCC junction. Three patients had successful ablation at RCC-LCC junction, and one patient at LCC. One patient had successful ablation at anterior interventricular vein-great cardiac vein junction. One patient had successful ablation at non-coronary cusp. During follow-up (12-30 months), one patient had recurrence of VA controlled by flecainide. The remaining patients were free of VA without medications.
Conclusions: Catheter ablation of VA originating from aortic cusps is safe and effective. CT image integration into electroanatomic mapping system can be helpful in this challenging ablation.