Wide-QRS Complex Tachycardia.

In a man with a wide-QRS complex tachycardia, a history of an inferior left ventricular scar, atrioventricular dissociation during the tachycardia, and a QRS morphology inconsistent with right or left bundle branch block exclude a diagnosis of supraventricular tachycardia with aberrant ventricular conduction due to bundle branch block or ventricular preexcitation and establish a diagnosis of ventricular tachycardia.