Coarctation of the aorta is a congenital (present at birth) heart defect involving a narrowing of the aorta. The aorta is the large artery that carries oxygen-rich (red) blood from the left ventricle to the body. It is shaped like a candy cane, with the first section moving up towards the head (ascending aorta), then curving in a C-shape as smaller arteries that are attached to it carry blood to the head and arms (aortic arch). After the curve, the aorta becomes straight again, and moves downward towards the abdomen, carrying blood to the lower part of the body (descending aorta).
The narrowed segment called coarctation can occur anywhere in the aorta, but is most likely to happen in the segment just after the aortic arch. This narrowing restricts the amount of oxygen-rich (red) blood that can travel to the lower part of the body. Varying degrees of narrowing can occur.
The more severe the narrowing, the more symptomatic the patient will be, and the earlier the problem will be noticed. In some cases, coarctation is noted in infancy. In others, however, it may not be noted until school age or adolescence.
Thirty percent to 40 percent of children with coarctation of the aorta also have a bicuspid aortic valve—a valve that has two leaflets instead of the usual three.
Coarctation of the aorta occurs in about 6 percent to 8 percent of all children with congenital heart disease. Boys have the defect twice as often as girls do.