Ostium primum atrial septal defect

Atrial septal defect (ASD) is a type of congenital heart disease, accounting for 30% of all congenital heart diseases. Ostium primum atrial septal defect is one type, also known as an unclosed ostium primum ASD, accounting for approximately 15%. The defect is located at the junction of the atrial septum and the endocardial cushion. It is often associated with a cleft in the anterior leaflet of the mitral valve, and occasionally with a cleft in the tricuspid valve. Compared to ostium secundum atrial septal defect, its pathophysiological changes are more severe, and the disease progresses more rapidly.