aortopulmonary fenestration /ā·ôr′tōpul″məner′ē/ [Gk, aerein + L, pulmoneus, lung, fenestra, window] , a congenital anomaly characterized by an abnormal fenestration in the ascending aorta and the pulmonary artery cephalad to the semilunar valve, allowing oxygenated and unoxygenated blood to mix, resulting in a decrease in the oxygen available in the peripheral circulation. Also called aortic septal defect, aortopulmonary window.
