Ventricular fibrillation induced by radiofrequency ablation for slow ventricular tachycardia associated with left ventricular dysfunction

A 59-year-old man with premature ventricular contractions (PVCs) and slow ventricular tachycardia (VT) underwent electrophysiologic testing. The left ventricular ejection fraction was 27%. Activation mapping showed the site of earliest activation to be the posterolateral site of the right ventricle inflow tract, and we considered this to be the focal mechanism underlying the PVCs/slow VT. Radiofrequency current delivered at this site induced a cluster of rapid ventricular beats (sustained VT) with the same QRS morphology as the PVCs, followed by ventricular fibrillation. The PVC/VT focus might have served as an abnormal automatic trigger and driver for the ventricular fibrillation.