AIM: The effectiveness and safety of antiarrhythmic agents, mostly digoxin and amiodarone given to prevent recurrences, were compared in 141 infants of less than 1 year (77% < 1 month) with re-entrant supraventricular tachycardia. RESULTS: Digoxin was the drug of first choice in 114 patients at a dose of 10-20 micrograms/kg/d and was effective in 74 cases (65%). Amiodarone was used as first line therapy or after failure of digoxin. It was given at a maintenance dose of 250 mg/m2/d, alone in 22 infants and together with digoxin in another 36; it was effective in 56 cases (96.5%). Early adverse events occurred in six patients receiving digoxin: ventricular fibrillation requiring cardioversion in three, two of whom had Wolff-Parkinson-White syndrome, significant sinus bradycardia in two, accidental overload in one. At further follow-up, one child treated with digoxin but having also gastroesophageal reflux, died suddenly at 3 months of age; autopsy was normal and the digoxin blood level was 3 ng/mL. Among the 58 infants who received amiodarone, there were no proarrhythmia, a slight and transient increase in TSH in six infants and only one required a short-term treatment for hypothyroidism. Prophylactic therapy was maintained for 6 to 12 months and only ten patients had recurrences in the year following withdrawal. CONCLUSION: Amiodarone was found to be safer and more effective than digoxin. No significant side-effect was demonstrated in infants receiving a short-term treatment. Amiodarone may be proposed as first line therapy for prophylaxis of re-entrant supraventricular tachycardia in infancy, especially for those patients with reentry and Wolff-Parkinson-White syndrome.
AIM: The effectiveness and safety of antiarrhythmic agents, mostly digoxin and amiodarone given to prevent recurrences, were compared in 141 infants of less than 1 year (77% < 1 month) with re-entrant supraventricular tachycardia. RESULTS:Digoxin was the drug of first choice in 114 patients at a dose of 10-20 micrograms/kg/d and was effective in 74 cases (65%). Amiodarone was used as first line therapy or after failure of digoxin. It was given at a maintenance dose of 250 mg/m2/d, alone in 22 infants and together with digoxin in another 36; it was effective in 56 cases (96.5%). Early adverse events occurred in six patients receiving digoxin: ventricular fibrillation requiring cardioversion in three, two of whom had Wolff-Parkinson-White syndrome, significant sinus bradycardia in two, accidental overload in one. At further follow-up, one child treated with digoxin but having also gastroesophageal reflux, died suddenly at 3 months of age; autopsy was normal and the digoxin blood level was 3 ng/mL. Among the 58 infants who received amiodarone, there were no proarrhythmia, a slight and transient increase in TSH in six infants and only one required a short-term treatment for hypothyroidism. Prophylactic therapy was maintained for 6 to 12 months and only ten patients had recurrences in the year following withdrawal. CONCLUSION:Amiodarone was found to be safer and more effective than digoxin. No significant side-effect was demonstrated in infants receiving a short-term treatment. Amiodarone may be proposed as first line therapy for prophylaxis of re-entrant supraventricular tachycardia in infancy, especially for those patients with reentry and Wolff-Parkinson-White syndrome.