A malformation of the heart in which the embryonic common PULMONARY VEIN was not incorporated into the LEFT ATRIUM leaving behind a perforated fibromuscular membrane bisecting the left atrium, a three-atrium heart. The opening between the two left atrium sections determines the degree of obstruction to pulmonary venous return, pulmonary venous and pulmonary arterial hypertension.
Also Known As:
Triatrial Heart; Cor Triatriatum Sinistrum; Subdivided Left Atrium; Atrium, Subdivided Left; Atriums, Subdivided Left; Heart, Triatrial; Hearts, Triatrial; Left Atrium, Subdivided; Left Atriums, Subdivided; Subdivided Left Atriums; Triatrial Hearts