Signs and symptoms of mitral valve regurgitation, which depend on its severity and how quickly the condition develops, can include:
- Blood flowing turbulently through your heart (heart murmur)
- Shortness of breath (dyspnea), especially with exertion or when you lie down
- Fatigue, especially during times of increased activity
- Cough, especially at night or when lying down
- Heart palpitations — sensations of a rapid, fluttering heartbeat
- Swollen feet or ankles
Mitral regurgitation is often mild and progresses slowly. You may have no symptoms for decades and be unaware that you have this condition, and it might not progress.
Your doctor might first suspect you have mitral regurgitation upon detecting a heart murmur. Sometimes, however, the problem develops quickly, and you may experience a sudden onset of severe signs and symptoms.
When to see a doctor
If you develop symptoms that suggest mitral valve regurgitation or another problem with your heart, see your doctor right away. Sometimes the first indications are actually those of mitral valve regurgitation's complications, including heart failure, a condition in which your heart can't pump enough blood to meet your body's needs.
Mitral valve regurgitation is classified as primary and secondary. Primary mitral regurgitation is caused by an abnormality in the mitral valve; secondary is caused by an abnormality in the left ventricle of the heart.
Possible causes of mitral valve regurgitation include:
- Mitral valve prolapse. In this condition, the leaflets and tendon-like cords supporting the mitral valve weaken and stretch so that with each contraction of the left ventricle, the valve leaflets bulge (prolapse) into the left atrium. This common heart defect can prevent the mitral valve from closing tightly and lead to regurgitation.
- Damaged tissue cords. Over time, the tissue cords that anchor the flaps of the mitral valve to the heart wall may stretch or suddenly tear, especially in people with mitral valve prolapse. A tear can cause substantial leakage through the mitral valve relatively suddenly and may require repair by heart surgery. Trauma to the chest also can rupture the cords.
- Rheumatic fever. Rheumatic fever — a complication of untreated strep throat and once a common childhood illness in the United States — can damage the mitral valve, leading to mitral valve regurgitation later in life. Rheumatic fever is rare in the United States, but still common in developing countries.
- Endocarditis. The mitral valve may be damaged by an infection of the lining of the heart (endocarditis) that can involve heart valves.
- Heart attack. A heart attack can damage the area of the heart muscle that supports the mitral valve, affecting the function of the valve. If the damage is extensive enough, a heart attack can cause sudden and severe mitral valve regurgitation.
- Abnormality of the heart muscle (cardiomyopathy). Over time, certain conditions, such as high blood pressure, can cause your heart to work harder, gradually enlarging your heart's left ventricle. This can stretch the tissue around your mitral valve, which can lead to leakage.
- Congenital heart defects. Some babies are born with defects in their hearts, including damaged heart valves.
- Certain drugs. Prolonged use of certain drugs, such as ergotamine, used to treat migraines and other conditions, can cause mitral valve regurgitation.
How the heart works
The heart, the center of your circulatory system, consists of four chambers. The two upper chambers, the atria, receive blood. The two lower chambers, the ventricles, pump blood.
Four heart valves open and close to let blood flow in only one direction through your heart. The mitral valve — which lies between the two chambers on the left side of your heart — comprises two flaps of tissue called leaflets.
The mitral valve opens when blood flows from the left atrium to the left ventricle. Then the flaps close to prevent the blood that has just passed into the left ventricle from flowing backward.
In mitral valve regurgitation, the mitral valve doesn't close tightly. With each heartbeat, blood from the left ventricle flows backward into the left atrium instead of moving forward into the aorta.
Several factors can increase your risk of mitral valve regurgitation, including:
- A history of mitral valve prolapse or mitral valve stenosis. However, having either condition doesn't necessarily mean you'll develop mitral valve regurgitation. A family history of valve disease also can increase risk.
- A heart attack. A heart attack can damage your heart, affecting the function of the mitral valve.
- Use of certain medications. People who take ergotamine and similar medicines for migraines and those who took pergolide (now off the market) have an increased risk of mitral regurgitation. Similar problems were noted with the appetite suppressants fenfluramine and dexfenfluramine, which are no longer sold.
- Infections such as endocarditis or rheumatic fever. Infections or the inflammation they cause can damage the mitral valve.
- Congenital heart disease. Some people are born with an abnormal mitral valve prone to regurgitation.
- Age. By middle age, many people have some mitral valve regurgitation caused by natural deterioration of the valve.
When it's mild, mitral valve regurgitation may not cause problems. However, severe, mitral valve regurgitation can lead to these complications:
Heart failure. Heart failure results when your heart can't pump enough blood to meet your body's needs. Severe mitral valve regurgitation places an extra strain on the heart because, with blood pumping backward, there is less blood going forward with each beat. The left ventricle gets bigger and, if untreated, weakens. This can cause heart failure.
Plus, pressure builds in your lungs, leading to fluid accumulation, which strains the right side of the heart.
- Atrial fibrillation. The stretching and enlargement of your heart's left atrium may lead to this heart rhythm irregularity in which the upper chambers of your heart beat chaotically and rapidly. Atrial fibrillation can cause blood clots, which can break loose from your heart and travel to other parts of your body, causing serious problems, such as a stroke if a clot blocks a blood vessel in your brain.
- Pulmonary hypertension. If you have long-term untreated or improperly treated mitral regurgitation, you can develop a type of high blood pressure that affects the arteries in the lungs (pulmonary hypertension). A leaky mitral valve can increase pressure in the left atrium, which can eventually cause pulmonary hypertension, which can lead to heart failure on the right side of the heart.
For any heart condition, see your doctor regularly so he or she can monitor you and possibly catch mitral valve regurgitation in its early stages, when it's more easily treatable. Also, be aware of conditions that contribute to developing mitral valve regurgitation, including:
- Rheumatic fever. If you have a severe sore throat, see a doctor. Untreated strep throat can lead to rheumatic fever. Fortunately, strep throat is easily treated with antibiotics.
- High blood pressure. Check your blood pressure regularly. Make sure it's well-controlled because high blood pressure contributes to heart disease.
- Mitral valve prolapse. If you have this or another condition that affects your heart valves, see your doctor regularly. Seek urgent medical care if you develop a fever or symptoms of an infection of your heart lining (endocarditis).
- Heart attack. To reduce your risk of heart attack, don't smoke, exercise regularly, manage your blood pressure and cholesterol, and eat a heart-healthy diet.