Incessant device-initiated wide complex tachycardia: What is the mechanism?

Wide complex tachycardia comprises a broad group of tachyarrhythmias in patients with cardiac implantable electronic devices. Standard maneuvers for establishing the correct diagnosis require careful interpretation in the presence of ventricular pacing. Furthermore, atypical forms of common arrhythmias may require a combination of maneuvers to be performed during an electrophysiology study to correctly identify the culprit arrhythmia and localize the appropriate region for targeted ablation. In this report, we describe a patient with a biventricular defibrillator who presented with incessant wide-complex tachycardia with associated ventricular pacing.