Fetal Echocardiography Practice Test

Ostium primum ASD sits in the lower part of the atrial septum and reflects a defect in the endocardial cushions that also contribute to the atrioventricular valves. Because the AV cushions are involved in forming both the lower septum and the AV valves, this defect almost universally comes with malformation of the AV valve, most characteristically a cleft in the mitral valve (an AV canal-type appearance). This mitral valve cleft can lead to mitral regurgitation and is the hallmark finding you’d expect with this condition.

Other findings listed aren’t the classic association. A bicuspid aortic valve and coarctation of the aorta are more characteristic of other congenital heart disease patterns and not specifically tied to Ostium primum ASD. A trabecular (inlet) VSD can be seen in AV canal-type defects but is not as defining as the cleft in the AV valve.