pediatrics
Atrial Septal Defect (ASD)
Classification
ASDs can be classified by location: Ostium secundum: A defect in the fossa ovalis—in the center (or middle) part of the atrial septum Sinus venosus: A defect in the posterior aspect of the septum, adjacent to the superior vena cava or inferior vena cava, and frequently associated with anomalous return of the right upper or lower pulmonary veins to the right atrium or vena cava Ostium primum: A defect in the anteroinferior aspect of the septum, a form of Atrioventricular Septal Defect (endocardial cushion defect) 