Aortic arch interruption with truncus arteriosus or aorticopulmonary septal defect.

Interruption of the aortic arch is commonly associated with cardiac malformations. The angiocardiographic appearance in the presence of coexistent truncus arteriosus or an aorticopulmonary septal defect may be very similar. Five patients with arch interruption, three of whom also had truncus arteriosus and two with an aorticopulmonary septal defect are analyzed and the pertinent literature reviewed. In the presence of a truncus arteriosus with arch interruption the aorta appears as an appendage arising anteriorly from a large "pulmonary trunk" with a single semilunar valve, whereas when there is an aorticopulmonary septal defect two separate great artery roots and two semilunar valves are visible. The angiographic features are best defined by a truncal root angiogram when there is a truncus arteriosus or by an aortic root angiogram in the presence of an aorticopulmonary fenestration.