Supravalvular aortic stenosis
Supravalvular aortic stenosis (SVAS) is a type of heart defect that develops before birth. A normal aortic valve, when open, allows the free flow of blood from the left ventricle to the aorta. When the valve narrows, as it does with stenosis, blood flow is impeded. Because it is more difficult for blood to flow through the valve, there is increased strain on the heart.
It is characterized by a narrowing (stenosis) of the section of the aorta just above the valve that connects the aorta to the heart (aortic valve). The severity of SVAS varies from person to person; some individuals may die in infancy while others never experience symptoms. If symptoms develop, they may include shortness of breath, chest pain, murmur, and/or eventual heart failure. Some affected individuals also have defects in other blood vessels, such as the pulmonary artery.
SVAS can also be associated with Williams syndrome.
