Aortic Stenosis Aortic stenosis is a narrowing or blockage of the aortic valve. The aorta is the main blood supplier to the rest of the body. Aortic stenosis happens when the valve leaflets become coated with deposits that change their shape and reduce blood flow through the valve. The left ventricle has to work harder to make up for the reduced blood flow. Over time, the extra work can weaken the heart muscle.
Aortic stenosis is more common among men.
In some cases, people are born with a bicuspid aortic valve, meaning the valve has 2 leaflets instead of 3. This may also cause aortic stenosis. In elderly patients, calcium deposits and the growth of fibrous tissue on the aortic valve can distort the leaflets or cause them to fuse together. This is called calcification, and it can make the different leaflets almost look like one. Other causes include a history of other valve diseases, coronary artery disease, or a heart murmur.