Subtotal cor triatriatum with left partial anomalous pulmonary venous return. Successful surgical repair in an infant.

A 10-week-old infant underwent successful repair of subtotal cor triatriatum associated with left-sided partial anomalous pulmonary venous return to the innominate vein. This unusual type of cor triatriatum represents an intermediate embryologic form between pure cor triatriatum and total anomalous pulmonary venous return. Important hemodynamic differences exist between this defect and pure cor triatriatum. Exact anatomic diagnosis prior to operation is highly desirable. To our knowledge, this case represents the first successful repair of this very rare congenital cardiac defect.