The combined use of amiodarone and class 1-C antiarrhythmic agents in children with intractable supraventricular tachyarrhythmias

Combined antiarrhythmic drug therapy is an occasionally necessary but problematic approach to the child with recalcitrant supraventricular tachycardia. There is little experience with the combined use of amiodarone and class 1-C agents (flecainide, propafenone and encainide) in children. To judge the efficacy and safety of this combination, we reviewed the case notes and results of investigation in all nine children with supraventricular tachycardia who received such therapy between 1984 and 1993. These nine children received combined therapy on 12 occasions. Five were infants with either atrioventricular reentrant tachycardia (n=3) or atrial ectopic tachycardia (n=2), and four were older children with atrial flutter seen after a Fontan procedure. Amiodarone was combined with flecainide on eight occasions, with propafenone on three occasions, and with encainide on one occasion. Both infants with atrial ectopic tachycardia were successfully controlled, but only one of three infants with atrioventricular reentrant tachycardia had successful control on combination therapy. In three of the four patients with atrial flutter, the combination was useful in reducing the number of arrhythmic episodes. Three infants suffered side effects. At electrophysiologic study to judge efficacy, ventricular tachycardia was induced in two patients (one infant and one Fontan patient), necessitating a change in the 1-C agent. One patient had skin rash due to flecainide and was placed on propafenone with success. One Fontan patient died of complications after an elective surgical procedure. No deaths occurred attributable to proarrhythmia. Thus, combined therapy with amiodarone and 1-C agents was found to be safe and fairly effective in children with certain types of intractable supraventricular tachycardia.