Cor triatriatum: congenital stenosis of the common pulmonary vein.

Cor triatriatum is the term given to a rare congenital abnorTnality of the heart in which a septum separates what is apparently one of the atria into upper posterior and lower anterior chambers. With few exceptions, the septum has always been present on the left side of the heart. Other names given to the same anomaly naturally reflect the authors' views concerning the nature and origin of the extra chamber. Thus Loeffler (1949) reported his case as a 'heart with pulmonary sinus' and Edwards, Du Shane, Alcott and Burchell (1951) have referred to 'stenosis of the common pulmonary vein'. From the functional aspect, three varieties of the condition have been described (Loeffler, 1949). In one, there is no communication between the accessory chamber and the left atrium. Death is inevitable immediately after delivery unless there is some other anomaly allowing blood to escape from the accessory chamber as in Case 3 of Edwards et al. (1951). At the other extreme there is an opening in the septum which is relatively large so that there is little or no obstruction to the flow of blood through the left side of the heart as in the patients of Loeffier (1949) and of Griffith (1903). In the intermediate variety the communication between the accessory chamber and the left atrium consists of one or more small openings which offer considerable obstruction to blood flow. The following is the report of a patient who comes into this last category.