Fetal Supraventricular Tachycardia with Hydrops Fetalis in a 20-year old primigravid

Abstract

INTRODUCTION: Fetal tachycardia can occur in approximately 0.4% to 0.6% of all pregnancies. The most common forms of fetal tachycardias are SVT and atrial flutter. Sustained tachyarrhythmia can lead to congestive heart failure, hydrops, severe neurologic morbidity, or fetal or neonatal demise. CASE: This is the case of a 20-year old female primigravid who, at 30 weeks age of gestation, experienced increased fetal heart rate. Fetal cardiogram showed a short ventriculo-atrial (VA) interval with a 1:1 atrio-ventricular (AV) conduction, and a rate of 210 to 220 bpm. Amniotic fluid index was 25.34 cm, suggestive of borderline polyhydramnios. Estimated fetal weight was 1,504 g. There was anechoic fluid surrounding the right lung suggestive of pleural effusion with an estimated volume of 12.0 mL. Fetal echocardiography showed an adequate-sized patent foramen ovale; and AV and VA concordance. The patient was first treated with intravenous digoxin, and then oral flecainide. The fetal heart rate converted to sinus rhythm on the 8th day of treatment. There were no immediate maternal and fetal complications noted.