Coarctation of the aorta: four unusual instances.

Four unusual instances of coarctation of the aorta are presented. Three coarctations were located proximal to the left subclavian artery, and the other was in the normal location with a patent ductus arteriosus and an anomalous distal right subclavian artery. Unusual coarctations can be identified on physical examination on the basis of variations of blood pressure and pulses in the upper extremities. Unilateral rib notching may be noted on chest roentgenogram, and an aortogram can delineate its exact location. Four separate means of surgical repair are described.