Objective: Highlight the management of a critically ill premature hydropic baby with refractory atrial flutter (AF) and successful outcome without neurologic sequel at 1 year of follow-up.

Case: A 23-year-old pregnant woman, G1P0, presented with fetal tachycardia at 32 weeks.

Results: Ultrasound revealed a hydropic fetus with fetal atrial rate (FHR) of 440 bpm and A:V block of 2:1. Transplacental therapy resulted in a temporary response with the combination of digoxin and flecainide, and subsequently digoxin plus sotalol. Termination of pregnancy at 34 weeks was performed for postnatal treatment, giving birth to a premature hydropic baby, weighing 3,320 grams. At birth flecainide failed to control the AF. Therefore, intravenous adenosine was started and successful conversion to normal sinus rhythm was temporally achieved. Finally, conversion to normal sinus rhythm with amiodarone plus digoxin was satisfactorily achieved and then long-term control with only oral flecainide. The hydropic signs gradually disappeared without any significant sequelae. The baby was healthy at one year of follow-up without any neurological sequelae.

Conclusion: This case may be evidence that combined therapy with amiodarone and digoxin is probably effective in treatment of refractory AF with hydropic changes, at least in some cases.

Keywords: Atrial flutter, Hydrops fetalis, Ultrasound