Ventricular Tachycardia Originating from Heart-Like Left Ventricular Diverticulum Diagnosed by Carto Merge System

Abstract

A 67 year-old man was referred to our hospital because of pre-syncope and palpitation. The 12-lead ECG recorded during ventricular tachycardia (VT) showed a right bundle branch block and left superior axis QRS morphology, consistent with that of left basal posterior wall origin. After admission, multidetector Computed Tomography (MDCT) showed no finding of coronary artery but left ventricular (LV) diverticulum of the left basal posterior wall. In the electrophysiological study, endocardial voltage mapping during sinus rhythm revealed the presence of a low voltage area in the LV diverticulum. Isolated delayed potential was recorded between low and normal voltage at the edge of LV diverticulum. Pace mapping at the delayed potential recording site produced the same QRS morphology as that of clinical documented VT and PVCs. However, given the thin walls of the LV diverticulum, cardiac surgery under general anesthesia rather than radiofrequency application by the catheter was indicated and performed. After surgery, VT and the PVCs disappeared on 24-hr Holter ECG. The patient was discharged without antiarrhythmic therapy and had no cardiac events during 6 months follow-up. This case illustrates how the CARTOMERGE system can allow our precise understanding of 3D anatomy of LV, accurate risk assessment of catheter ablation and optimal therapeutic strategy for VT originating from LV anomaly.