Unstable accelerated idioventricular rhythm in a neonate with congenital heart disease.

Neonatal accelerated idioventricular rhythm (AIVR) has been documented previously in neonates with congenital heart disease (CHD), although no cases have led to significant clinical deterioration or required placement of a permanent pacemaker.1–3 We present the first case of a neonate with complex single-ventricle physiology that developed AIVR after surgical correction of CHD, which degenerated to unstable wide complex tachycardia with multiple episodes of significant hemodynamic compromise. We discuss the management of this usually benign rhythm, which led to permanent pacing in the setting of complex CHD.