DIGOXIN OR FLECAINIDE FOR PROPHYLAXIS OF SUPRAVENTRICULAR TACHYCARDIAIN INFANTS

Objectives. This study compared the safety and efficacy of digoxin and flecainide in the prophylaxis of supraventricular tachycardia in infa nts. Background. Recurrence of supraventricular tachycardia in infants is common, Digoxin is the conventional drug of first choice for proph ylaxis, but its efficacy has not been tested in a controlled clinical trial, and there is no consensus on the drug of choice when digoxin is ineffective. Methods. We reviewed retrospectively the records of all infants with supraventricular tachycardia due to atrioventricular (AV) reentry admitted to our hospital between January 1986 and December 19 93. Results. Thirty-nine infants presented crith sustained AV reentran t tachycardia at age 1 to 330 days (median 12). Intravenous flecainide ,vas required to maintain immediate control in six patients who were t hen treated with oral flecainide. The other 33 patients were treated w ith oral digoxin, There was no recurrence of tachycardia in 14 (42%) o f the 33 patients (95% confidence interval [CI] 25% to 61%). In the ot her 19 patients (58%) (95% CI 39% to 75%), digoxin was replaced by ora l flecainide because of multiple recurrence of tachycardia, Full contr ol was achieved in all 19 of these patients (100%) (95% CI 82% to 100% ) and in 5 of the 6 patients treated with both intravenous and oral fl ecainide. Thus, overall, flecainide was effective in 24 (96%) of 25 pa tients (95% CI 80% to 100%). Conclusions. Comparison with previous nat ural history studies suggests that digoxin is ineffective in the proph ylaxis of supraventricular tachycardia. Oral flecainide was effective in a small number of infants, with no adverse effects (95% CI 0% to 12 %), and may now be preferred as the primary prophylactic agent.