Ventricular Tachycardia Originating from Apical Septum in a Case with Dilated Cardiomyopathy: Correlation of Electroanatomical Data with Post-Mortem Histology

Abstract

Introduction: We report a 41-year-old male of pleomorphic ventricular tachycardia (VT) complicated with dilated cardiomyopathy, treated with RF ablation, followed by autopsy of the heart. Case Presentation: 12-lead ECG during one of VTs exhibited rS pattern in leads V1 to V6, consistent with septoapical origin. Bipolar endocardial voltage map revealed small zone of low voltage in the left ventricular (LV) apex. Good pacemap was obtained from the right ventricular (RV) apex, but was not obtained from the LV apex. Activation map revealed the earliest activation site in both RV and LV apex. No diastolic potentials during the ongoing VT were detected. The VT was terminated by several RF deliveries at LV apex, but remained inducible. On autopsy of the heart, scattered fibrosis was observed in midmyocardium of LV, and was more prominent in septum than in LV free wall. The lesions produced by RF delivery were non-transmural in RV septum (a depth of 6 mm) and LV free wall (2.5 mm). Conclusion: The VT originated from apical, intraseptal injured myocardium with a breakthough to the RV, which could not effectively ablate from either apex.