LAUSR

A 30-year-old primigravida African-American female was referred to our fetal cardiac center after an abnormal 20-week prenatal ultrasound. Fetal echocardiogram (Acuson S3000 ultrasound system, Siemens Healthcare, Erlangen, Germany) performed at 20 weeks and 6 days gestation demonstrated moderate to severe right atrial enlargement without evidence of other structural or functional abnormality. Notably, the tricuspid valve appeared to have normal morphology with no significant regurgitation. Biventricular systolic function was normal with no evident arrhythmia, and all Doppler evaluations were normal. The mother and fetus were followed by fetal cardiology and findings remained stable over time (Image 1 and Supporting Information Video 1). The baby girl was delivered at 40 weeks and 2 days gestation via Cesarean section performed for prolonged rupture of membranes and failed induction of labor. APGAR scores were 8 and 8 at 1 and 5 minutes respectively, with initial cyanosis and saturation in the high 80’s. When leaving the delivery room, however, saturation was 92%, and thereafter in the mid 90’s. She was transferred to neonatal intensive care unit to confirm prenatal findings and close monitoring. Chest X-ray demonstrated cardiomegaly (Image 2A). The echocardiogram demonstrated a severely dilated right atrium in the setting of a normal tricuspid valve (Supporting Information Videos 2 and 3), trivial tricuspid valve regurgitation, moderate sized patent ductus arteriosus with low velocity bidirectional shunting, patent foramen ovale with bidirectional shunting, and normal right ventricular systolic function. The pulmonary valve had normal function, and the pulmonary valve annulus, main pulmonary artery, and branch pulmonary arteries measured within normal limits. Computed tomography (CT) angiography of the chest (Aquilion One, Toshiba, Otawara, Japan) was performed, which confirmed the finding of severely dilated right atrium and moderately enlarged right atrial appendage (Images 2B and 2D). The patient was monitored on telemetry and no arrhythmia was noted, which was also confirmed on 24 h Holter monitoring. The patient was discharged home with close outpatient follow up. She was doing well at her last follow up (at 12 months of age) with no arrhythmia, thrombus formation, or any other progression of her disease.