Incessant "ventricular tachycardia" in a patient with non-ischemic cardiomyopathy. What is the tachycardia mechanism?

We present an uncommon and unique arrhythmia in a patient with non-ischemic cardiomyopathy and dual chamber implantable cardioverter defibrillator presenting with palpitations and dyspnea. While surface electrocardiogram suggested irregular narrow complex tachycardia, evaluation of stored electrograms from implantable cardioverter defibrillator revealed incessant episodes of non-sustained ventricular tachycardia. The patient underwent electrophysiological study and successful ablation of the arrhythmia with complete resolution of symptoms. We discuss the underlying tachycardia mechanism and challenges in the diagnosing and management of this unusual rhythm disorder. (c) 2015 Elsevier Inc. All rights reserved.