Amiodarone-induced 2 to 1 atrioventricular block in association with prolongation of the QT interval.

The potential for development of 2 to 1 atrioventricular conduction in children with prolongation of the QT interval has been previously reported secondary to electrolytic disturbances. We report here a child who developed 2 to 1 atrioventricular conduction with prolongation of the QT interval following treatment with amiodarone for refractory supraventricular tachycardia. We highlight the importance of electrocardiographic monitoring to assess for those at risk of amiodarone toxicity, which may be manifested by prolongation of the QT interval and the simultaneous loss of atrioventricular conduction, and of equal importance the need for prompt conversion to an alternative anti-arrhythmic agent.