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|This narrated animation shows how valves are supposed to function and what can go wrong with them. (Animation provided courtesy of Medtronic.)
Your heart’s valves are essential for proper circulation because they regulate the direction that your blood flows. Proper blood flow is necessary for your body to receive necessary oxygen supply. When the heart valves are defective or don’t work the way they should, it can put your heart and other organs at risk.
Valve disease can affect one or more of the four valves in the heart (mitral, aortic, tricuspid and pulmonary). Most often it causes one or both of the following problems:
- Regurgitation - The valve’s tissue flaps (leaflets), which control the flow and direction of the blood, do not fully close or the edges do not fully meet, which causes blood to leak back into the heart.
- Stenosis - The leaflets cannot open fully to allow enough blood to flow through.
- Atresia -The heart valve does not have an opening for blood to flow through.
One way to understand regurgitation and stenosis is to think of a door. A door opens one way and closes very firmly in the other. That’s how a healthy valve works, too. But when a valve doesn’t close firmly, blood can leak through (regurgitation). And, if the valves get stuck, like hinges in a door can over time, the blood has trouble getting through (stenosis).
Some problems with the valves are present at birth (congenital valve disease) while others develop over time as we age (acquired valve disease).
Congenital Valve Disease
Although it can be diagnosed at any age, congenital valve disease occurs when a valve does not form correctly in the developing fetus. Leaflets may be missing or misshapen, or the valve may have no opening at all. Most commonly, congenital valve disease affects the pulmonary and aortic valves.
Some of the most common types of congenital valve disease include the following:
- Pulmonary atresia - The heart does not have a functioning pulmonary valve or there is a hole between the two bottom chambers of the heart and no direct connection between the heart and the lung’s blood vessels.
- Pulmonary stenosis - The heart’s pulmonary valve is thick and its opening is smaller than normal. As a result, blood cannot flow normally from the heart through the valve and to the lungs.
- Tricuspid atresia - The tricuspid valve, which lies between the heart’s upper right chamber (the right atrium) and lower right chamber (the right ventricle), does not develop. As a result, it prevents oxygen-depleted blood that is returning to the right atrium from the body from directly flowing into the right ventricle (the chamber that normally pumps blood to the lungs where it picks up oxygen).
- Bicuspid aortic valve disease - The aortic valve is formed with only two leaflets instead of three (or two of the three leaflets are stuck together), which increases the chance of the leaflets sticking together over the course of your lifetime and interfering with the flow of blood. Unlike the congenital valvular problems discussed above, bicuspid aortic valves can be undetected during infancy and childhood. This condition may be discovered during middle age when the two leaflets thicken and scar and begin to restrict blood flow. Bicuspid aortic valves can run in families. They can also be associated with abnormal enlargement of the main body artery (the ascending aorta).
If you are a parent of a child with valvular heart disease, you may want to learn more about children and heart disease. Click here.
Acquired Valve Disease
Valves that are formed properly at birth can still develop problems related to aging, infection, heart attack damage and other events that cause wear and tear to the valves. Valve function can also be affected by a build-up of calcium deposits on the valve leaflets, making them stiff and inflexible. The aortic and mitral valves are most frequently affected by acquired heart valve disease.
Two of the most common types of acquired valvular heart disease are aortic stenosis and mitral regurgitation. Let's look at each.
Aortic stenosis a problem with the aortic valve that can happen over time, even if the aortic valve was formed properly at birth. Infection, aging and calcium deposits are a few examples of the problems that can cause the aortic valve to stiffen or close up the valve between the lower left chamber of the heart (the left ventricle) and the main artery that carries blood from the heart to the body. When the aortic valve is narrowed (stenosis), it limits the flow of blood from the heart to the aorta, causing blood to back up in the heart. This back-up of blood places pressure and strain on the heart’s pumping chambers and can affect the proper function of other heart valves. Over time, the pressure may contribute to enlarged heart chambers and back-up of blood in the lungs, which leads to congestive heart failure.
Click here to learn how aortic stenosis can be treated.
Mitral regurgitation is one of the most common condition involving the valves of the heart. The mitral valve controls blood flow between the upper chamber (the atrium) and the lower chamber (the ventricle) on the left side of the heart. A leaky mitral valve (mitral regurgitation) can develop when the valve flaps (leaflets) do not close effectively. This can happen either because the valve flaps are damaged or defective, or because the heart has become enlarged, stretching the valve opening so much that the flaps no longer meet in the center.
Click here to learn more about mitral regurgitation and how it can be treated.
Risk Factors for Acquired Valve Disease
Risk factors for acquired valve disease include:
- Age. Men over 65 and women over 75 are at greater risk for acquired valve disease. With age, the tissue flaps (valve leaflets) that open and close to allow blood to regulate the direction and flow of the blood through the heart can become hardened and thick. This limits movement and flexibility, both of which are needed for them to work as they should. Sometimes the cords of tissue that hold valve flaps to the heart can become stretched or torn, which can also interfere the valve's proper function.
- Heart attack. A heart attack can cause damage to the heart and scarring that affect how your valves function. Learn about heart attack here.
- Heredity. Some valve problems, such as bicuspid aortic valve or mitral valve prolapse, can run in families.
- Calcium deposits. These deposits occur most often on the aortic valve but can also occur on the mitral valve. These calcium deposits are not related to calcium in your diet, calcium supplements or medications such as calcium channel blockers, so don’t stop taking your medication without checking with your doctor.
- Endocarditis. This infection of the valves of the heart is typically caused when bacteria from another part of your body, such as your mouth, travels to your heart. Patients who already have pre-existing heart valve damage are more likely to acquire endocarditis, and endocarditis can damage heart valves as well. Learn more about endocarditis here.
- Rheumatic fever. Untreated strep throat can lead to rheumatic fever, which in turn can damage the heart's valves, causing them to thicken. This increased thickness in the valves can restrict their ability to open and close properly. Rheumatic fever can affect any of the four heart valves, but mostly involves the aortic and mitral valves. Acute rheumatic heart valve problems occur less frequently in developed countries with ready access to antibiotics. Antibiotics should not be used to treat all fevers or infections, however. Learn about rheumatic fever here.
- High blood pressure. Persistent high blood pressure can cause your heart to work harder, which can enlarge the heart's pumping chamber (the left ventricle). As it enlarges, tissues around the heart valves can become stretched, preventing the valve from closing properly. Learn more about high blood pressure here.
- Cardiomyopathy (heart muscle disease). When the heart becomes enlarged, this can lead to the tissue ring surrounding the valves to become stretched, causing leakage. Primarily, this affects the mitral valve. You can learn about cardiomyopathies here.
- Connective tissue diseases. Because heart valves are made of tissue similar to that which makes up the connective tissues of the body and the walls of the blood vessels, they can be affected as well. For instance, Marfan syndrome can have aortic and mitral valve involvement.
You may never know the cause of your valve disease, but if you have symptoms, seek help. Click here to review the symptoms of valve disease. Your doctor will work with you to diagnose your heart valve problem and discuss your treatment options.
Click here for more information on the treatment of valve disease.
If you have a valve problem, make sure to schedule visits with your doctor on a regular basis. You can also download and print Questions to Ask Your Doctor about Heart Valve Disease as a reminder of what you want to ask and to help you take notes during your visit.