Aortopulmonary Septal Defect

Excerpt

An aortopulmonary (AP) septal defect, also known as an AP window, is one of the rarest congenital heart defects accounting for less than 0.5% of forms of congenital heart disease. This defect can occur in isolation or concurrently with other forms of congenital heart disease such as a ventricular septal defect, interruption of the aortic arch, tetralogy of Fallot, and very rarely, coronary artery anomalies. By definition, the AP window is a direct "side to side" connection of the ascending aorta to the main pulmonary artery but with the formation of a normal aortic valve and a right ventricular outflow tract, differentiating it from truncus arteriosus. Embryologically an AP window develops when there is incomplete septation of the great arteries.