Treatment of fetal supraventricular tachycardia with flecainide acetate after digoxin failure.

Transplacentally administered digoxin is the drug of choice for the treatment of fetal supraventricular tachycardia. We describe a case of fetal supraventricular tachycardia associated with fetal hydrops that did not respond to digoxin treatment because of a lack of transplacental passage. In contrast, flecainide acetate crossed the placenta and cured the fetus. The clinical implications of this new treatment are discussed.