Radiofrequency Catheter Ablation with the Use of a Noncontact Mapping System for Ventricular Tachycardia Originating from the Aortic Sinus Cusp —A Case Report—

Here we present a 15‐year old female in whom an idiopathic ventricular tachycardia (VT) originating from the left aortic sinus cusp was eliminated by radiofrequency catheter ablation (RFCA) under navigation using a noncontact mapping system (NCM). The dynamic activation map constructed with the NCM clearly identified a VT focus in the left aortic sinus cusp, from which the activation spread out to the entire left ventricle. At that site, the virtual unipolar electrogram recorded with the NCM was the same as the contact unipolar electrogram in terms of morphology and timing, a pre‐systolic potential preceding the QRS complex by 40 msec was recorded by contact bipolar electrogram and rapid pacing during sinus rhythm resulted in a perfect pace match. RFCA at that site eliminated the VT and the patient has had no recurrence during 10 months of follow‐up.