Aortic valve stenosis (AS) is a disease of the aortic valves in which the opening of the valve is narrowed. When the opening of the aortic valve becomes narrowed or constricted (stenotic), the blood cannot be pumped adequately and the pressure in the left ventricle increases. Over time, the left ventricle compensates by thickening its walls in order to maintain adequate pumping pressure. In later stages, the left ventricle dilates, the wall thins, and the systolic function deteriorates.
A normal size aortic valve is the size of a half-dollar and a significantly stenotic valve may range in size of a dime to a pinhole.
Degree of aortic stenosis can be assessed by echocardiography and heart catheterization. In adults, critical aortic stenosis is defined as a mean gradient >70 mmHg and/or an aortic valve area of < 0.6 cm2.
When the aortic valve is severely stenotic, it may need to be replaced with a new valve. This is done surgically. However, percutaneous and catheter based procedures are available for patients who are not candidates for surgical valve replacement.