Fetal arrhythmias are not uncommon in pregnancy. The
diagnosis can be established on routine ultrasound scan.
Fetal supraventricular tachycardia (SVT) is the most
common cause of fetal tachycardia. If left undiagnosed and
untreated, these fetuses may develop cardiac failure,
hydrops fetalis and eventually death.
We report two fetuses diagnosed antenatally to have fetal
SVT. Both fetuses were in cardiac failure and were
successfully treated with maternal administration of antiarrhythmic
medications. Digoxin, and in severe instances, a
combination with flecanaide significantly improved fetal
outcomes and prevented fetal mortality. The long term
prognosis of such patients are good.