Prenatal diagnosis of cor triatriatum sinister in association with hypoplastic left heart syndrome.

Cor triatriatum sinister is a rare congenital heart defect related to incomplete common pulmonary vein resorption into the primitive heart. This lesion usually presents with pulmonary venous obstruction and can occur in association with left-sided obstructive lesions such as hypoplastic left heart syndrome (HLHS). In the context of HLHS, the presence of cor triatriatum sinister carries additional surgical and prognostic implications. Fetal diagnosis can enable appropriate counseling of the family and guide optimal peri- and postnatal management. The reported case represents the first prenatal description of cor triatriatum sinister in association with HLHS.