Cor triatriatum

Abstract

The failure of absorption of the common pulmonary vein creates this malformation and results in a left atrium (LA) divided by an abnormal fibromuscular diaphragm into a posterosuperior chamber receiving the pulmonary veins and an anteroinferior chamber having LA appendage and mitral orifice. The interrelation between the divided atrial chambers may be large, small, or absent, depending on the size of the opening in the membrane which defines the degree of obstruction to pulmonary venous return. Rises in both pulmonary venous pressures may result in an even severe pulmonary artery hypertension [1, 2].