This content requires Flash Player.
This narrated animation shows how valves are supposed to function and what can go wrong. (Animation provided courtesy of Medtronic.)
Your heart’s valves are an essential feature of its structure because they regulate the direction and flow of the blood that replenishes the oxygen supply throughout your body. (Click here if you would like to learn more about the structure of the heart, its valves, and how they work.) But when the 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, or leaflets, that control the flow and direction of the blood, do not fully close, which causes blood to leak back into the heart.
- Stenosis - The leaflets cannot open fully to allow enough 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 (atrium) and lower right chamber (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, which increases the chance of the leaflets sticking together over the course of your lifetime and interfering with the flow of blood. Unlike the preceding congenital valvular problems, bicuspid aortic valves are usually undetected during infancy and childhood. It is discovered during middle age when the two leaflets thicken and scar and begin to restrict blood flow.
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 buildup of calcium deposits on the leaflets that makes them stiff and inflexible. The aortic and mitral valves are most frequently affected by acquired heart 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, limiting movement and flexibility they need 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.
- Calcium deposits. These deposits occur most often on the aortic valve but can also occur on the mitral valve. By the way, 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 heart valve damage are more likely to acquire endocarditis, and endocarditis can damage heart valves as well.
- 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. This valve damage typically shows up years or decades after the episode of rheumatic fever.
- A pre-existing valve problem. If you already have a valve problem, it can affect blood flow and cause more clots to form on the surface of the valve. Bacteria are more likely to attach and collect where these clots have formed.
- Immune system diseases that affect aortic and mitral valves
- Tumors in the digestive tract. If these tumors spread to liver and lymph nodes, they can affect the tricuspid and pulmonary valves
- Metabolic disorders
- Weight loss medications
- Radiation therapy to the chest
- 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.
- Cardiomyopathy (heart muscle disease).
- Aortic aneurysms.
- Connective tissue diseases.
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 take notes during your visit.