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 (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. But it can get worse over 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 is can be linked to other valve or skeletal problems. Some rare instances of MVP are hereditary.
In secondary MVP, another disease is linked to MVP. Often the valve flaps are not thickened. Prolapse occurs for other reasons. The prolapse may be from:
- Damage caused by decreased blood flow from 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. Hypertrophic cardiomyopathy 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:
- Fast or irregular heartbeats (palpitations). 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 linked to 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. This is also called treadmill or exercise ECG. 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 from a floppy mitral leaflet, tear (rupture) of the cords, or extreme lengthening of the valve, you may need transcatheter mitral valve repair, surgical repair, or valve replacement.
What are possible 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. You may be at high risk for endocarditis if you have had a valve replaced. You may need to take 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.
Key points about mitral valve prolapse
- Mitral valve prolapse (MVP) is the bulging (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 (regurgitation).
- 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.
- 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.
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.