Acute inferior cardiac inflow obstruction resulting from inadvertent surgical closure of a prominent Eustachian valve mistaken for an atrial septal defect.

A 5-month-old boy with a VACTERL syndrome underwent cardiac surgery for correction of a common arterial trunk and closure of an atrial septal defect. A prominent Eustachian valve was mistaken for the atrial septum and surgically closed. Thirty months later, after gradual shrinking of the foramen ovale with associated reduction of the right-to-left shunt, the boy presented with acute symptoms of a lower inflow obstruction, characterized by hepatomegaly and engorged abdominal vein pattern (Medusa's head). The boy was reoperated successfully after the condition had been recognized.