Accelerated idioventricular rhythm associated with propranolol treatment in a child.

Accelerated idioventricular rhythm (AIVR) is a ventricular arrhythmia most commonly seen in adults with underlying cardiac disease. It is important to establish the diagnosis when it occurs to differentiate this benign phenomenon from dangerous ventricular tachycardia. We present the case of a healthy child who developed episodes of AIVR associated with propranolol treatment. Her 24-hour electrocardiography recording showed AIVR with difference between sinus and ventricular beats. The arrhythmia resolved with the discontinuation of propranolol, and eventually the case was in sinus rhythm. This patient is the first case of AIVR associated with propranolol treatment in the literature.