Foetal supraventricular tachycardia with hydrops fetalis: a role for direct intraperitoneal amiodarone.

Introduction: Persistent foetal tachyarrythmias complicated by hydrops fetalis carry a poor prognosis, with foetal death reported in excess of a quarter despite treatment. We present our experience with direct intraperitoneal amiodarone administration in eight hydropic foetuses with resistant supraventricular tachycardia.
Methods: Amiodarone was injected slowly into foetal peritoneal cavity under ultrasound guidance. All mothers were loaded with oral amiodarone before the procedure and maintained on it. The procedure was repeated guided by foetal rhythm.
Result: All eight cases had severe hydrops with a median foetal heart rate of 255 bpm (range 240-300 bpm), and the median gestational age was 27+1 weeks (range 21-33+3 weeks) at presentation. In six cases, the average time for supraventricular tachycardia to revert to sinus rhythm from the first procedure was 11.5 days. In one case, intravascular injection of amiodarone into the umbilical vein was performed before intraperitoneal injection, which resulted in conversion to sinus rhythm sustained until delivery. In the last case, supraventricular tachycardia and severe hydrops persisted and the baby was delivered 5 days later at 34 weeks' gestation. Hydrops resolved in five foetuses with a mean resolution time of 28.4 days. The mean gestational age at delivery was 34+5 days and seven of eight cases survived beyond the neonatal period with good postnatal outcomes.
Conclusion: Intraperitoneal administration of amiodarone is a relatively simple and effective strategy in refractory supraventricular tachycardia complicated by severe hydrops. The intraperitoneal route assures delivery of the drug to the severely hydropic foetus and enables a bolus dose to be delivered for sustained absorption.