Left subclavian steal, interrupted aortic arch, complete transposition of the great vessels and single left ventricle.

Congenital subclavian steal consists of atresia of the proximal end of the subclavian artery, while the blood supply to the distal portion of the subclavian artery originates from the circle of Willis. It should be suspected in complicated malformations of the heart associated with marked hypoplasia or interruption of the aortic arch. Minimal differences in blood pressure determinations may be an important clue in the diagnosis of this anomaly. The diagnosis may be confirmed by angiography with careful attention to late arterial phase films.