Supravalvular aortic stenosis(SVAS) is a congenital heart defect. As the name suggests, SVAS means the section of the aorta located just above the aortic valve is narrowed. SVAS accounts for 8% to 14% of all congenital aortic stenosis. Three different types of SVAS are recognized: hourglass, membranous, and hypoplasia of aortic arch. Hourglass type SVAS is the most common. Membranous type is the result of the fibrous and/or fibromuscular semicircular diaphragm with a small central opening stretched across the aortic lumen. Diffuse hypoplasia of the ascending aorta is the third.