Nonischemic cardiomyopathy: Simultaneous epicardial and endocardial mapping and ablation

Abstract

A 66-year old male with a history of viral myocarditis presented for management of monomorphic ventricular tachycardia (VT). Epicardial and endocardial mapping under RV parahisian paced rhythm showed significant low voltage areas in the free wall of RV. Isochronal late activation map revealed a clear deceleration zone (DZ) on the RV free wall of both epicardium and endocardium. Activation mapping and entrainment during VT identified a clockwise circuit in RV free wall and the isthmus was consistent with the DZ. Epicardial ablation at the isthmus was initially attempted and VT changed in 18 s to another untolerated VT, which ultimately required direct current cardioversion. Combined epicardial and endocardial ablation was performed targeting the DZ. VT was noninducible at the end of the procedure.