Coarctation of the aorta.

oarctation of the aorta is a discrete narrowing of the aorta, the main blood vessel carrying oxygen-rich blood from the heart to the body, causing an obstruction to blood flow. Coarctation is a common congenital heart defect, an abnormality in the structure of the aorta that is present at birth or shortly after birth. It may be identified in infants or older children or adults and successfully repaired at any age. Treatment options to relieve the aortic obstruction include surgery and cardiac catheterization procedures. Blood leaves the heart through the aortic valve to the aorta, which gives off branches to the head and arms in an area called the aortic arch. The aorta then turns downward (descending aorta) to carry blood to the lower body. Typical coarctation occurs in the descending part of the aorta beyond the aortic arch (see Figure) The obstruction makes it hard for the blood to get beyond the narrowed area. The blood pressure before the obstruction is high, and the blood pressure beyond the obstruction is abnormally low. If the aortic narrowing is severe, the left ven-tricle (main pumping chamber in the heart) may not be able to pump against the very high pressure and begin to fail. This presentation occurs in some new-borns; it is rare in older children. In association with coarctation, the aor-tic arch, the area between the ascending aorta and the descending aorta, may be smaller than normal (hypo-plastic), particularly in newborns. Over time, extra blood vessels called collaterals develop to carry blood around the area of obstruction. Most patients with coarctation have a bicuspid aortic valve, meaning the aortic valve, located between the left ventricle and the aorta, has 2 leaflets instead of the normal 3. Other cardiac defects can occur with coarctation, including abnormalities on the left side of the heart or more complex defects. This discussion will focus on the presentation, diagnosis, and treatment options for coarctation, not the other associated congenital heart defects. Coarctation and other abnormalities on the left side of the heart occur more often in boys than girls. These obstructions in the left side of the heart can run in families, and a genetic tendency is likely. When coarctation occurs in girls, it can be associated with Turner syndrome, a chromosomal abnormality with other related abnormal findings. The presenting signs of coarctation vary with age. Patients with severe narrowing present in the newborn period. …