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Heart Valve Types

A normal, healthy human heart has four valves. The valves are found at the exits from the four heart chambers. While all the heart valves serve the same purpose--to ensure blood flows in only one direction--they are each slightly different. In the case of valvular disease, a heart valve may need to be replaced surgically. Surgeons use two types of prosthetic valves for this purpose.

  1. Mitral Valve

    • The mitral valve is located between the left atrium (upper heart chamber) and the left ventricle (lower heart chamber). The mitral valve is also called the bicuspid valve. This is because it comprises two strong, thin flaps, called leaflets. The leaflets open to allow blood to flow from the atrium into the ventricle and then close to prevent flow in the opposite direction.

    Tricuspid Valve

    • The tricuspid valve, which consists of three leaflets, is located between the right atrium and the right ventricle. Like the mitral valve, the tricuspid valve ensures blood flows only from the atrium to the ventricle.

    Aortic Valve

    • The aortic valve is located between the left ventricle and the aorta, the body's largest artery. This valve normally is composed of three leaflets; however, in a small percentage of the population two of the leaflets are fused together. The aortic valve ensures that blood flows from the left ventricle into the aorta. It prevents backward flow from the aorta to the left ventricle.

    Pulmonic Valve

    • The pulmonic valve, which also has three leaflets, lies between the right ventricle and the pulmonary artery, which carries blood to the lungs. Its function is similar to that of the aortic valve, ensuring that blood flows out of the ventricle.

    Mechanical Valves

    • Several options exist when a heart valve needs replacement. One option is to use a mechanical valve, which is built using man-made materials. It is designed to last a lifetime. However, patients with these valves must remain on medication to prevent blood clots for the rest of their lives.

    Biological Tissue Valves

    • The other option for valve replacement is a biological tissue valve, which comes either from a living source, such as a cow or pig, or from a deceased human. Patients with these valves usually do not need to take medication to prevent blood clots. However, these valves typically do not last as long as mechanical valves, necessitating additional replacement surgery when they wear out.

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