Extended Multi-Drug Maternal Therapy For Refractory Supraventricular Tachycardia In Premature Hydrops Fetalis

Background: Fetal supraventricular tachycardia (SVT) is a reversible cause of fetal hydrops, with better outcomes if detected early and reverted in utero. Modern imaging allows accurate diagnosis and maternal anti-arrhythmic therapy can be practiced ensuring in utero cardioversion.Case presentation: We present a case of preterm fetal hydrops due to SVT successfully reverted in utero by multidrug maternal therapy. The mother presented to our tertiary care hospital at 32 weeks' gestation with a fetal heart rate of 229 beats/min with evidence of mild fetal pericardial effusion and ascites. Under strict maternal monitoring, the treatment was started with parenteral digoxin. Flecainide, sotalol and amiodarone were introduced sequentially based on the response until cardioversion was achieved at 35 weeks with no maternal side effects. She labored spontaneously and delivered a 2.6 kg baby boy 4 days after the successful cardioversion. The baby was discharged home on day 7 on oral amiodarone with outpatient follow-up. Digoxin monotherapy failed in our case, possibly due to evidence of hydrops and a sequential multi-drug therapy was required for an extended duration of up to 2 weeks to achieve cardioversion successfully.Conclusions: Our report suggests that multi-drug therapy is more successful in cases of SVT with fetal hydrops, titrated according to fetal response and maternal tolerance, although a prolonged period of therapy might be required to achieve the desired clinical effect.