Mitral Valve Prolapse
What is mitral valve prolapse?
The mitral valve allows blood to flow from the left atrium to the left ventricle in the heart. Mitral valve prolapse (MVP) is the bulging (or prolapse) of one or both of the mitral valve flaps (leaflets) into the left atrium when the heart contracts. When the flaps don't close properly, blood leaks backward. This is called regurgitation. Regurgitation may cause a heart murmur, an abnormal sound in the heart caused by turbulent blood flow. When regurgitation is present, it’s generally mild although it can get worseover time.
The mitral valve is located between the left atrium and the left ventricle and has 2 flaps. Normally the flaps are tightly closed by small tendon or "cords" that connect the flaps to the muscles of the heart. This closure prevents blood from flowing backwards. In MVP, the flaps enlarge and stretch inward toward the left atrium, sometimes "snapping" during heart contraction. This may allow some back-flow or regurgitation of blood into the left atrium.
MVP usually does not need to be treated because it is rarely a serious condition, and it doesn't damage the heart. However, regular checkups with a doctor are advised.
What causes MVP?
The cause of MVP is unknown, but most cases are thought to be inherited. There are 2 forms of MVP: primary and secondary.
Primary MVP means the mitral valve is abnormal because of one or more of these changes:
- One or both of the flaps are too large and thick
- The flap surfaces are scarred
- The tendon cords are thinner or longer than they should be
- There are fibrin deposits on the flaps
Primary MVP is most often an isolated disease but can be associated with other valvular or skeletal abnormalities. Some rare instances of MVP are hereditary.
In secondary MVP, another disease is associated with MVP. Often, the valve flaps are not thickened but rather prolapse occurs for other reasons. The prolapse or bulging may be due to:
- Damage caused by decreased blood flow (due to coronary artery disease) to the muscles attached to the tendon cords
- Functional changes in the heart muscle
- Damage to valve structures caused by heart attack, rheumatic heart disease, valve infection, or hypertrophic cardiomyopathy (this is when the left ventricle of the heart is larger than normal)
- Damage caused by a connective tissue disorder such as Marfan syndrome
Who is at risk for MVP?
MVP affects both sexes and people of all ages. Factors that may increase the risk of MVP include:
- Graves disease (a condition that affects the thyroid gland)
- Certain connective tissue disorders, such as Marfan syndrome
- Scoliosis and other skeletal problems
- Some types of muscular dystrophy
What are the symptoms of MVP?
MVP may not cause any symptoms. Symptoms may vary depending on the degree of prolapse present. The presence of symptoms doesn't necessarily match the severity of MVP.
These are the most common symptoms of MVP:
- Palpitations (fast or irregular heartbeats). This may be the result of irregular heartbeats or just the sensation of the valve closing when the heart rhythm is normal.
- Chest pain. Chest pain associated with MVP is different from chest pain associated with coronary artery disease. Usually the chest pain is not like classic angina, such as pain with exertion, but it can happen often, can be very uncomfortable, and can affect your quality of life.
- Exercise intolerance
Depending on the severity of the mitral regurgitation or leak, the left atrium or left ventricle may become enlarged, leading to symptoms of heart failure. These symptoms include weakness, tiredness, dizziness, and shortness of breath.
The symptoms of mitral valve prolapse may look like other medical conditions or problems. Always see a healthcare provider for a diagnosis.
How is mitral valve prolapse diagnosed?
You may have no noticeable symptoms. Your doctor may hear a click or murmur during a routine physical exam. The "click" is created by the stretched flaps snapping against each other during contraction. The murmur is caused by the blood leaking back into the left atrium. This may be the only sign of MVP.
Along with a complete medical history and physical exam, your provider may order these tests to diagnose MVP:
- Electrocardiogram (ECG). This test records the strength and timing of the electrical activity of the heart. It shows abnormal rhythms and can sometimes detect heart muscle damage. Small sensors are taped to your skin to pick up the electrical activity.
- Chest X-ray. An X-ray may be done to check your lungs and see if your heart is enlarged.
- Transthoracic echocardiogram (echo, or TTE).This is a noninvasive test that uses sound waves to evaluate the heart's chambers and valves. The echo sound waves create an image on the monitor as an ultrasound transducer is passed over your chest above the heart. Echocardiography is the most useful diagnostic test for MVP.
For more severe symptoms, other tests may be done. These may include:
- Stress test (also called treadmill or exercise ECG).This ECG is done while you walk on a treadmill to monitor the heart during exercise. Breathing and blood pressure rates are also checked.
- Cardiac catheterization. With this procedure, X-rays are taken after a contrast agent (dye) is injected into an artery to look for any narrowing, blockages, or other changes in certain arteries. The function of the heart and the valves may be checked, too.
- Cardiac MRI. This is an imaging test that takes detailed pictures of the heart. It may be used to get a more precise look at the heart valves and heart muscle, or to prepare for heart valve surgery.
How is mitral valve prolapse treated?
MVP usually doesn't need to be treated because it is rarely a serious condition, and it doesn't damage the heart. Regular checkups with your doctor are advised.
If you have heart rhythm changes, you may need medicines that control fast heart rhythms or irregular heartbeats. In most cases, you will also need to limit stimulants, such as caffeine and cigarettes, to control symptoms.
If you have atrial fibrillation or severe left atrial enlargement, you may need treatment with an anticoagulant (blood thinner) to keep clots from forming. This can be in the form of aspirin ,warfarin therapy, or other newer blood thinners
If you have symptoms of dizziness or fainting, it's important to stay well hydrated by drinking plenty of fluids.
If severe mitral regurgitation is due to a floppy mitral leaflet, rupture (tear) of the cords, or extreme lengthening of the valve, you may needa catheter-based procedure called a transcatheter mitral valve repair, surgical repair, or valve replacement.
What are the complications of mitral valve prolapse?
Rarely, bacteria that enter the bloodstream can cause endocarditis, an infection of the inner lining of the heart chambers and valves. This risk is higher in people with MVP because the deformed mitral valve flap can attract bacteria that are in the bloodstream. Gum infections and tooth decay can cause endocarditis, so regularly flossing and brushing your teeth can help prevent it. People at high risk for endocarditis (such as those who have had a valve replaced) may be given antibiotics before dental work and certain types of surgery.
When should I call my healthcare provider?
Call your healthcare provider if your symptoms get worse or if you have new symptoms.
- Mitral valve prolapse (MVP) is the bulging (or prolapse) of one or both of the mitral valve flaps into the left atrium during the contraction of the heart. One or both of the flaps may not close properly, allowing the blood to leak backward (called regurgitation).
- The cause of MVP is unknown, but is thought to be inherited.
- MVP affects both sexes and people of all ages. Some things that may increase the risk of MVP include Graves disease; certain connective tissue disorders, such as Marfan syndrome; scoliosis and other skeletal problems; and some types of muscular dystrophy.
- MVP may not cause any symptoms, and symptoms may vary depending on the degree of prolapse present. The most common symptoms include palpitations (fast or irregular heartbeats) and chest pain.
- People with MVP often have a click or murmur that’s heard during a routine physical exam.
- MVP usually does not need to be treated because it is rarely a serious condition, and it does not damage the heart.
- People with heart rhythm changes may need to be treated with medicines to control tachycardias (fast heart rhythms).
- MVP is usually harmless and does not shorten life expectancy.
- Rarely, bacteria that enter the bloodstream can cause endocarditis, an infection of the inner lining of the heart chambers and valves. This risk is higher in people with MVP. People at high risk for endocarditis (such as those who have had a valve replaced) may be given antibiotics before dental work and certain types of surgery.
Tips to help you get the most from a visit to your healthcare provider:
- Know the reason for your visit and what you want to happen.
- Before your visit, write down questions you want answered.
- Bring someone with you to help you ask questions and remember what your provider tells you.
- At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
- Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
- Ask if your condition can be treated in other ways.
- Know why a test or procedure is recommended and what the results could mean.
- Know what to expect if you do not take the medicine or have the test or procedure.
- If you have a follow-up appointment, write down the date, time, and purpose for that visit.
- Know how you can contact your provider if you have questions.