Aortic Valve Stenosis

The aortic valve controls the direction of blood flow from the left ventricle to the aorta. Under some circumstances, the aortic valve becomes narrower than normal, impeding the flow of blood. This is known as aortic valve stenosis.

What causes aortic stenosis?

Stenosis can be caused by rheumatic fever or simply by "wear and tear" occurring over many years of opening and closing every second of the day. Certain illness and disease can contribute to the development of valve problems, including auto immune disease (such as arthritis), infections and kidney failure. One of the most common causes of aortic valve narrowing is a congenital defect in which the aortic valve has only two leaflets instead of three.

What are the symptoms?

Aortic stenosis is most often diagnosed when it is asymptomatic and can sometimes be detected during routine examination of the heart and circulatory system. Some symptoms are dizziness, fainting, angina and congestive heart failure.

What are the treatment options?

Treatment requires replacement of the diseased valve with an artificial heart valve. The patient should discuss the options with their physician, as there are two different valve types that can be used: mecanical valves and tissue valves.

Tissue heart valves are usually made from animal tissues, either animal heart valve tissue or animal pericardial tissue. The tissue is treated to prevent rejection and calcification. Tissue valves tend to wear out faster with increased flow demands - such as with a more active (typically younger) person. They typically last 10-15 years in less active (typically older) patients, but wear out faster in younger patients. When a tissue valve wears out and needs replacement, the person must undergo another valve replacement surgery. For this reason, mechanical valves are often recommended for younger patients to prevent the increased risk and inconvenience of another valve replacement.

Mechanical valves are designed to outlast the patient, and have typically been stress-tested to last several hundred years. Although they are long-lasting and generally only one surgery is needed, there is an increased risk of blood clots forming with mechanical valves. As a result, mechanical valve recipients must generally take anti-coagulant (blood thinning) drugs such as warfarin for the rest of their lives, which makes the patient more prone to bleeding. Mechanical valves are constructed entirely of man made materials usually pyrolite carbon, a diamond hard material attached to a Dacron sewing ring to attach it to the patient's tissue.