The atrial septal defect (ASD) most commonly associated with partial anomalous pulmonary venous return (PAPVR) is:

B. Sinus venosus defect.

DISCUSSION: Although partial anomalous return of the pulmonary veins can occur with any of the ASDs listed, it is particularly common with sinus venosus defects and is considered by many to be part of this lesion. The most common anomaly is drainage of the right superior pulmonary vein to the lateral aspect of the superior vena cava.