Clinical Overview
Reviewed by Brian R. Robinson, MD

Heart valves keep blood flowing through the heart by opening and closing their leaflets, which are attached at the base of the valves. When the leaflets are open, blood can move through the valves; when they are closed, the leaflets form a seal to prevent blood flow. The four valves are the pulmonary valve, the aortic valve, the tricuspid valve, and the mitral valve.

Heart valve disease occurs when one or more of the four valves in the heart do not work correctly. The two main types of valve disease are valvular stenosis (including aortic valve stenosis and pulmonary valve stenosis) and insufficiency.

Illustrated by David DiAngelis Copyright © Body1, Inc.

Valvular stenosis occurs when a valve opening is smaller than usual due to stiffened or fused leaflets, limiting the flow of blood. The narrower the valve opening becomes, the harder the heart must work to pump blood through it. This decreases blood flow to the rest of the body. The usual size of the valve opening is approximately the size of a 50-cent piece. Stenosis can reduce the opening to the size of a dime or smaller.

Valvular insufficiency, also called regurgitation, incompetence, or “leaky valve,” occurs when a valve does not form a tight seal upon closure. Without tight closure, some blood may leak backwards across the valve. As the leak worsens, the heart must work harder to compensate for the leaky valve, potentially lessening blood flow to the rest of the body.

Heart valve disease can be either congenital (present at birth) or acquired. In some cases, the cause of heart valve disease is unknown. Heart attack, high blood pressure, and coronary artery disease can also cause valve disease.

Congenital valve disease may mean that the valves may be the improper size or the leaflets may be malformed. In most cases, the aortic and pulmonary valves are affected. The most common congenital valve disease is bicuspid aortic, a type of aortic stenosis where the aortic valve has only two leaflets instead of three.

Acquired valve disease may be due to changes in the structure of the valve, or infection. Some of the infections that can affect heart valves are:

• Rheumatic fever, which is caused by untreated streptococcal infection, such as strep throat. Penicillin has dramatically reduced heart valve disease due to rheumatic fever.
  
• Endocarditis, a disease that occurs when germs enter your blood stream and attack the lining of your heart valves. Most often, the result is leaky heart valves.