Congenital abnormality of the aorta involving obstruction at the point at which it leaves the heart, just beyond the point at which the arteries leading to the head and the arms branch off. The rest of the body can be supplied adequately with blood only if it is pumped vigorously past the obstructed part of the aorta, and in order to do this blood pressure in the part of the aorta in front of the obstruction and in the arteries of the head and arms has to be kept high; thus the left ventricle has to work very hard, and signs of overload can show over the course of years (heart failure). Coarctation usually causes little discomfort as long as the left ventricle has sufficient strength to pump blood past the obstruction. Possible symptoms are shortness of breath during exertion and a feeling that the feet are always cold. Tests show that blood pressure is high in the arms and low in the legs, and no pulse can be felt in the groin. Treatment is by surgical removal of the obstructed section of the aorta and suture of the two ends; an artificial bridge may be fitted between them.