Benefit of Pacing and Beta-Blockers in Idiopathic Repetitive Polymorphic Ventricular Tachycardia

An 18-year-old woman presented with recurrent exercise-induced syncopal episodes and severe systolic dysfunction. ECG monitoring disclosed repetitive polymorphic ventricular complexes, paroxysms of bidirectional ventricular tachycardia, and nonsustained bursts of slow polymorphic ventricular tachycardia that increased in length and rate during exercise. Ventricular arrhythmias were refractory to medical treatment, which included verapamil and beta-blockers. Addition of permanent atrial pacing to beta-blocker therapy suppressed the arrhythmias and reversed systolic impairment in the following months.