Intrauterine digoxin treatment of fetal paroxysmal tachycardia. Case report.

A patient with fetal paroxysmal supraventricular tachycardia (PST) with a heart rate above 300 beats/minute in the 29th week of pregnancy is described. The fetus showed signs of severe cardiac failure and was, therefore, digitalized by giving the mother 0.5 mg digoxin intravenously on the first day and the 0.25 mg oral digoxin daily throughout the pregnancy. After one day a normal rhythm was observed. The patient was delivered of a healthy girl after 38 weeks of pregnancy. Digoxin concentrations in samples of umbilical cord vein and artery, intrapartum scalp capillary, and amniotic fluid were almost equal, but somewhat lower than in simultaneously obtained maternal serum. Intrauterine digoxin treatment of fetuses with PST is discussed.