A Case of Ventricular Tachycardia Originated above the Pulmonary Artery Valve and Treated by the Catheter Ablation in the Separated Two Exits

Abstract

A 24-year-old female was seen our hospital because of frequent palpitation. Twelve-leads ECG showed the ventricular tachycardia with left bundle branch block and inferior axis (VT1) with stable hemodynamic, and catheter ablation was performed. VT1 was provoked easily by the infusion of the isoproterenol, and it incessantly appeared. VT1 showed the near-perfect pacemap at the right ventricular outflow tract (RVOT) septum at first, it naturally changed to another VT (VT2) which had larger R wave in the inferior leads, and transitional zone shifted from V2-3 to V3-4. Appearance of the VT2 indicated the existence of the two different exits of the VT. After the termination of the VT1 by the application at the RVOT septum, VT2 began to appear continuously. Pacemap above the pulmonary artery valve showed the same morphologies as VT2, and clear discrete prepotential was identified at this site. Application at this site terminated the VT2, and all of the VTs become impossible to be provoked. We report a case of VT which had separated two exits, and was treated by the applications at each of the two exits.