A 9-year-old boy with hypertension has no palpable femoral pulses. Coarctation of the aorta is suspected. The following is/are true:

a. The most common associated abnormality is a bicuspid aortic valve

b. Chest radiograph is likely to show rib notching

d. In infancy, coarctation may present with a pink upper body and cyanotic lower body

Coarctation of the aorta occurs just distal to the origin of the left subclavian artery and results from contraction of ectopic tissue from the ductus arteriosus. The most common associated abnormality is a bicuspid aortic valve. Extensive collateral development involves the mammary and intercostal arteries producing rib notching on the chest radiograph. In infancy, flow to the lower body is from the ductus arteriosus before it closes, producing differential cyanosis. The “paradoxical hypertension” seen postoperatively is thought to relate to sympathetic nerve stimulation and does not reflect an incomplete repair.