Table 2. Commonly used medications for the chronic treatment of supraventricular tachycardia Digoxin Propranolol Sotalol Amiodarone Flecainide Propafenone Verapamil Atenolol Nadolol Digoxin is a sodium-potassium exchange pump inhibitor that has neuro-humoral effects and effects on cardiac conduction. Its efficacy as an antiarrhythmic drug is attributed to direct atrioventricular nodal blocking properties, combined with parasympathetic (vagal) activation, which slows sinus rate, decreases conduction velocity, and increases atrioventricular nodal refractoriness. For decades, digoxin has been reported to be the preferred medication to prevent recurrence of SVT in infants [1, 2], and it remains a common choice [3, 4]. In one retrospective review of 26 cases of infant SVT, Pfammatter & Stockler found that 65% had no recurrences on prophylactic digoxin therapy [3]. Deal et al reported that 61% of infants were treated with digoxin and that 37% of this group required additional or combination therapy, most commonly with propranolol [2].