Transcatheter management of subtotal cor triatriatum sinister: a rare anomaly.

Subtotal cor triatriatum sinister (partially divided left atrium) is characterized by a membrane dividing the left atrium into two portions: a dorsal accessory proximal chamber that receives part of the pulmonary venous return and a small restrictive defect in the membrane that obstructs blood flow from the accessory chamber to the left atrium and results in unilateral pulmonary venous hypertension. This clinical entity is very rarely reported in the literature. This first report of successful transcatheter management of a subdivided left atrium obstructing right pulmonary venous drainage discusses the anatomic, morphologic, and procedural details.