Aortic stenosis occurs when the aortic valve didn't form properly. A normal valve has three parts (leaflets or cusps), but a stenotic valve may have only one cusp (unicuspid) or two cusps (bicuspid), which are thick and stiff.

Sometimes stenosis is severe and symptoms occur in infancy. Otherwise, most children with aortic stenosis have no symptoms. In some children, chest pain, unusual tiring, dizziness or fainting may occur. The need for surgery depends on how severe the stenosis is. In children, the surgeon may be able to enlarge the valve opening. Although surgery may improve the stenosis, the valve remains deformed. Eventually, replacing the valve with an artificial one may be needed.

A procedure called balloon valvuloplasty has been used in some children who have aortic stenosis. During cardiac catheterization, a special catheter containing a balloon is placed across the constricted or narrowed valve. Then the balloon is inflated, and the valve is stretched open. The long-term results of this procedure are still being studied.

Children with aortic stenosis need lifelong medical follow-up. Even mild stenosis may worsen over time. Also, surgical relief of a blockage is sometimes incomplete. After surgery the valve keeps working in a mildly abnormal way. Some patients may have to limit how much they can do of some kinds of exercise. Check with your pediatric cardiologist about these exercise limits.  Children with aortic stenosis risk an infection of the valve (endocarditis) before and after treatment.  It needs to be determined whether your child will need to take antibiotics before certain dental procedures to help prevent endocarditis.