Anomalous Connection of Right Pulmonary Veins to Superior Vena Cava with Interatrial Communications

an interatrial communication in an unusually cephalad location has been diagnosed at cardiac catheterization in 8 patients. These patients had the clinical features seen in patients who have atrial septal defects in the region of the fossa ovalis. Differentiation was accomplished by (1) the roentgenographic position of the catheter in the right superior pulmonary vein, (2) demonstration of an abnormally high oxygen saturation of the blood in the superior vena cava, (3) the presence of a small right-to-left shunt from the superior vena cava and the absence of such a shunt from the inferior vena cava, and (4) demonstration of similar drainage of blood from the right superior pulmonary vein and superior vena cava. The syndrome is considered to be an anomaly of pulmonary venous development while the atrial septum forms normally.