Obstruction to pulmonary venous return is associated with which of the following anomalies?

B. Infracardiac (Type III) total anomalous pulmonary venous connection (TAPVC).

C. Pulmonary vein stenosis.

D. Cor triatriatum.

E. Supracardiac (Type I) TAPVC.

DISCUSSION: Obstruction to pulmonary venous return is the most important factor affecting circulatory function when pulmonary venous anomalies exist. This obstruction is most prevalent and severe in patients with infracardiac TAPVC, but it also occurs in as many as 50% of patients with supracardiac TAPVC and 20% of patients with intracardiac TAPVC to the coronary sinus. Obstruction to pulmonary venous return is also the primary pathophysiologic effect of both pulmonary vein stenosis and cor triatriatum. Obstruction, however, is rare with partial anomalous pulmonary venous connection, especially with the common form of PAPVC to the superior vena cava.