Catheter Ablation of Ventricular Tachycardia Beneath an Endoventricular Patch

A 70-year-old male with a history of ischemic heart disease with a left ventricular ejection fraction of 35% was referred for ablation to control recurrent episodes of ventricular tachycardia (VT) despite amiodarone therapy and a previous failed catheter ablation attempt. He had undergone coronary artery bypass grafting 20 years ago, and reoperation for mitral valve repair and endoventricular patch reconstruction (Dor procedure) of an anteroapical left ventricular aneurysm 10 years ago. After informed written consent was obtained, catheter mapping and ablation were performed with saline irrigated-tip catheter using electroanatomic mapping (CARTO; Biosense Webster, Diamond Bar, CA). A monomorphic VT with right bundle-branch block morphology in V1 was inducible and hemodynamically tolerated. Intracardiac echocardiography showed a pouch beneath the patch, consistent with dehiscence of a portion of the endoventricular patch, which had been recognized shortly after surgery 10 years previously (Figure 1). No thrombus was evident in the left ventricle (LV) or the pouch. Three-dimensional shells of the LV, the patch, and the apical aneurysmal pouch were separately …