Polymorphic Ventricular Tachycardia Induced by Left Ventricular Pacing

A 67-year-old woman with advanced heart failure accompanying idiopathic dilated cardiomyopathy had a broad QRS complex on the ECG and significant inter- and intraventricular asynchrony as shown by tissue Doppler echocardiography. She had no history of syncope, no documentation of any ventricular arrhythmias, and no metabolic or electrolyte abnormalities. Implantation of a biventricular pacemaker was indicated. When left ventricular stimulation was started, …