Hemodynamic considerations for prenatal treatment of severe Ebstein anomaly with circular shunt based on two cases and review of the literature.

Prenatal severe Ebstein anomaly might be complicated by a circular shunt. In these cases, persistently elevated right atrial and venous pressure (due to severe tricuspid regurgitation) is complicated by a systemic ineffective blood shunt via a DA, resulting in diminished end-organ perfusion and acidosis, due to overall low cardiac output. Affected fetuses are at a significantly higher risk of intrauterine fetal demise. Reduction of ductal flow by prenatal treatment with nonsteroidal anti-inflammatory drugs has recently been described as a potential treatment option. However, published data are limited and management during the antenatal course is not well defined. We provide a literature review to propose a possible algorithm for prenatal assessment and initiation of treatment.