What Is Heart Valve Disease?

Heart valve disease is a condition in which one or more of your heart valves don't work properly. The heart has four valves: the tricuspid (tri-CUSS-pid), pulmonary (PULL-mun-ary), mitral (MI-trul), and aortic (ay-OR-tik) valves.

These valves have tissue flaps that open and close with each heartbeat. The flaps make sure blood flows in the right direction through your heart's four chambers and to the rest of your body.

Healthy Heart Cross-Section

The illustration shows a cross-section of a healthy heart, including the four heart valves. The blue arrow shows the direction in which oxygen-poor blood flows from the body to the lungs. The red arrow shows the direction in which oxygen-rich blood flows from the lungs to the rest of the body.

Birth defects, age-related changes, infections, or other conditions can cause one or more of your heart valves to not open fully or to let blood leak back into the heart chambers. This can make your heart work harder and affect its ability to pump blood.

Overview

How the Heart Valves Work

At the start of each heartbeat, blood returning from the body and the lungs fills the heart's two upper chambers. The mitral and tricuspid valves are located at the bottom of these chambers. As the blood builds up in the upper chambers, these valves open to allow blood to flow into the lower chambers of your heart.

After a brief delay, as the lower chambers begin to contract, the mitral and tricuspid valves shut tightly. This stops blood from flowing backward.

As the lower chambers contract, they pump blood through the pulmonary and aortic valves. The pulmonary valve opens to allow blood to flow from the right lower chamber into the pulmonary artery. This artery carries blood to the lungs to get oxygen.

At the same time, the aortic valve opens to allow blood to flow from the left lower chamber into the aorta. This aorta carries oxygen-rich blood to the body. As the contraction ends, the pulmonary and aortic valves shut tightly. This stops blood from flowing backward into the lower chambers.

For more information on how the heart pumps blood, see the animation in the "Heart Contraction and Blood Flow" section of the Diseases and Conditions Index article on How the Heart Works.

Heart Valve Problems

Heart valves can have three basic kinds of problems:

• Regurgitation (re-GUR-ji-TA-shun), or backflow, occurs when a valve doesn’t close tightly. Blood leaks back into the chamber rather than flowing forward through the heart or into an artery.
• In the United States, backflow is most often due to prolapse. "Prolapse" is when the flaps of the valve flop or bulge back into an upper heart chamber during a heartbeat. Prolapse mainly affects the mitral valve, but it can affect the other valves as well.
• Stenosis (ste-NO-sis) occurs when the flaps of a valve thicken, stiffen, or fuse together. This prevents the heart valve from fully opening, and not enough blood flows through the valve. Some valves can have both stenosis and backflow problems.
• Atresia (a-TRE-ze-AH) occurs when a heart valve lacks an opening for blood to pass through.

You can be born with heart valve disease or you can acquire it later in life. Heart valve disease that develops before birth is called a congenital (kon-JEN-i-tal) valve disease. Congenital heart valve disease can occur alone or with other congenital heart defects.

Congenital heart valve disease usually involves pulmonary or aortic valves that don't form properly. These valves may not have enough tissue flaps, they may be the wrong size or shape, or they may lack an opening through which blood can flow properly.

Acquired heart valve disease usually involves the aortic or mitral valves. Although the valve is normal at first, disease can cause problems to develop over time.

Both congenital and acquired heart valve disease can cause stenosis or backflow.

Outlook

Many people have heart valve defects or disease but don't have symptoms. For some people, the condition will stay largely the same over their lifetime and not cause any problems.

For other people, the condition will worsen slowly over time until symptoms develop. If not treated, advanced heart valve disease can cause heart failure, stroke, blood clots, or sudden death due to sudden cardiac arrest.

Currently, no medicines can cure heart valve disease. However, lifestyle changes and medicines can relieve many of the symptoms and problems linked to heart valve disease. They also can lower your risk of developing a life-threatening condition, such as stroke or sudden cardiac arrest. Eventually, you may need to have your faulty heart valve repaired or replaced.

Some types of congenital heart valve disease are so severe that the valve is repaired or replaced during infancy or childhood or even before birth. Other types may not cause problems until you're middle-aged or older, if at all.

Author/Source: National Heart, Lung & Blood Institute, Division of the National Institutes of Health [NIH]

Retrieved: December 2007