Mitral Valve Prolapse

Normal Mitral Valve

The mitral valve controls blood flow between the upper and lower chambers of the left side of the heart. The upper chamber is called the left atrium. The lower chamber is called the left ventricle.

The mitral valve allows blood to flow from the left atrium into the left ventricle, but not back the other way. The heart also has a right atrium and ventricle, separated by the tricuspid valve.

With each heartbeat, the atria contract and push blood into the ventricles. The flaps of the mitral and tricuspid valves open to let blood through. Then, the ventricles contract to pump the blood out of the heart.

When the ventricles contract, the flaps of the mitral and tricuspid valves close. They form a tight seal that prevents blood from flowing back into the atria.

Mitral Valve Prolapse

In MVP, when the left ventricle contracts, one or both flaps of the mitral valve flop or bulge back (prolapse) into the left atrium. This can prevent the valve from forming a tight seal. As a result, blood may leak from the ventricle back into the atrium. The backflow of blood is called regurgitation.

MVP doesn’t always cause backflow. In fact, most people who have MVP don’t have backflow and never have any related symptoms or problems. When backflow occurs, it can get worse over time and it can change the heart’s size and raise pressure in the left atrium and lungs. Backflow also raises the risk of heart valve infections.

Medicines can treat troublesome MVP symptoms and help prevent complications. Some people will need surgery to repair or replace their mitral valves.

Causes of Mitral Valve Prolapse

Most people who have the condition are born with it. MVP tends to run in families. Also, it's more common in people who are born with connective tissue disorders, such as Marfan syndrome.

In people who have MVP, the mitral valve may be abnormal in the following ways:

• The valve flaps may be too large and thick.
• The valve flaps may be "floppy." The tissue of the flaps and their supporting "strings" are too stretchy, and parts of the valve flop or bulge back into the atrium.
• The opening of the valve may stretch.

These problems can keep the valve from making a tight seal. Some people's valves are abnormal in more than one way.

Risk Factors for Mitral Valve Prolapse

Mitral valve prolapse (MVP) affects people of all ages and both sexes; however, aging raises the risk of developing the disease.

Certain conditions have been associated with MVP, including:

• A history of rheumatic fever
• Connective tissue disorders, such as Marfan syndrome or Ehlers-Danlos syndrome
• Graves’ disease
• Scoliosis and other skeletal problems
• Some types of muscular dystrophy

Signs, Symptoms, and Complications of Mitral Valve Prolapse

Most people who have mitral valve prolapse (MVP) aren't affected by the condition. They don't have any symptoms or major mitral valve backflow.

When MVP does cause signs and symptoms, they may include:

• Palpitations (feelings that your heart is skipping a beat, fluttering, or beating too hard or too fast)
• Shortness of breath
• Cough
• Fatigue (tiredness), dizziness, or anxiety
• Migraine headaches
• Chest discomfort

MVP symptoms can vary from one person to another. They tend to be mild but can worsen over time, mainly when complications occur.

Mitral Valve Prolapse Complications

MVP complications are rare. When present, they're most often caused by the backflow of blood through the mitral valve.

Mitral valve backflow is most common among men and people who have high blood pressure. People who have severe backflow may need valve surgery to prevent complications.

Mitral valve backflow causes blood to flow from the left ventricle back into the left atrium. Blood can even back up from the atrium into the lungs, causing shortness of breath.

The backflow of blood strains the muscles of both the atrium and the ventricle. Over time, the strain can lead to arrhythmias. Backflow also increases the risk of infective endocarditis (IE). IE is an infection of the inner lining of your heart chambers and valves.

Arrhythmias

Arrhythmias are problems with the rate or rhythm of the heartbeat. The most common types of arrhythmias are harmless. Other arrhythmias can be serious or even life threatening, such as ventricular arrhythmias.

If the heart rate is too slow, too fast, or irregular, the heart may not be able to pump enough blood to the body. Lack of blood flow can damage the brain, heart, and other organs.

One troublesome arrhythmia that MVP can cause is atrial fibrillation (AF). In AF, the walls of the atria quiver instead of beating normally. As a result, the atria aren't able to pump blood into the ventricles the way they should.

AF is bothersome but rarely life threatening, unless the atria contract very fast or blood clots form in the atria. Blood clots can occur because some blood "pools" in the atria instead of flowing into the ventricles. If a blood clot breaks off and travels through the bloodstream, it can reach the brain and cause a stroke.

Infection of the Mitral Valve

A deformed mitral valve flap can attract bacteria in the bloodstream. The bacteria attach to the valve and can cause a serious infection called infective endocarditis (IE). Signs and symptoms of a bacterial infection include fever, chills, body aches, and headaches.

IE doesn't happen often, but when it does, it's serious. MVP is the most common heart condition that puts people at risk for this infection.

If you have MVP, you can take steps to prevent IE. Floss and brush your teeth regularly. Gum infections and tooth decay can cause IE.

Diagnosing Mitral Valve Prolapse

Mitral valve prolapse (MVP) is often detected during a routine physical exam when your doctor listens to your heart with a stethoscope.

Stretched valve flaps can make a clicking sound as they shut. If the mitral valve is leaking blood back into the left atrium, your doctor may hear a heart murmur or whooshing sound.

These abnormal heart sounds may come and go, and your doctor may not hear them at the time of an exam, even if you have MVP. Other test and procedures include:

• Echocardiography (echo): The most useful test for diagnosing MVP. This painless test uses sound waves to create a moving picture of your heart that shows its size, shape, and how well your heart chambers and valves are working. Echo can show prolapse of the mitral valve flaps and backflow of blood through the leaky valve.
• Stress echo is echocardiography done before and after a stress test. During a stress test, you exercise or take medicine given by your doctor to make your heart work hard and beat fast. This test shows whether you have decreased blood flow to your heart.
• Transesophageal echocardiography (TEE) is a form of echo that is done by placing a tiny probe in your esophagus to get a closer look at the mitral valve. 
• Doppler ultrasound is part of an echo test that shows the speed and direction of blood flow through the mitral valve.
• A chest X-ray may be used to look for fluid in your lungs or to show whether your heart is enlarged.
• An EKG (electrocardiogram) is a simple test that records your heart's electrical activity. An EKG can show how fast your heart is beating and whether its rhythm is steady or irregular. This test also records the strength and timing of electrical signals as they pass through your heart.

Treatment for Mitral Valve Prolapse

Most people who have mitral valve prolapse (MVP) don’t need treatment because they don’t have symptoms and complications.

Even people who do have symptoms may not need treatment. The presence of symptoms doesn’t always mean that the backflow of blood through the valve is significant.

People who have MVP and troublesome mitral valve backflow may be treated with medicines, surgery, or both.

The goals of treating MVP include:

• Correcting the underlying mitral valve problem, if necessary
• Preventing infective endocarditis, arrhythmias, and other complications
• Relieving symptoms

Medicines

Medicines called beta blockers may be used to treat palpitations and chest discomfort in people who have little or no mitral valve backflow.

If you have significant backflow and symptoms, your doctor may prescribe:

• Blood-thinning medicines to reduce the risk of blood clots forming if you have atrial fibrillation.
• Digoxin to strengthen your heartbeat.
• Diuretics (fluid pills) to remove excess sodium and fluid in your body and lungs.
• Medicines such as flecainide and procainamide to regulate your heart rhythms.
• Vasodilators to widen your blood vessels and reduce your heart’s workload. Examples of vasodilators are isosorbide dinitrate and hydralazine.

Surgery

Surgery is done only if the mitral valve is very abnormal and blood is flowing back into the atrium. The main goal of surgery is to improve symptoms and reduce the risk of heart failure.

Depending on the severity of the mitral valve defect, mitral valve repair or mitral valve replacement may be needed. At Cardiac Partners, expert heart surgeons perform mitral valve repair and replacement using minimally invasive techniques.

• Mitral valve repair is surgery to repair the valve that controls blood flow through the left side of the heart. This procedure leaves a person with their own functioning tissue, and doesn't require blood-thinning medication over the long term.
• Mitral valve replacement uses either a mechanical or a biological valve to replace the malfunctioning valve. Mechanical valves are man-made and can last a lifetime, but patients must take blood-thinning medicines for the rest of their lives. Biological valves don't require taking blood-thinning medicines, but these valves weaken over time and often last only about 10 years.
• Transcatheter valve therapy is performed by interventional cardiologists who repair leaky mitral valves by implanting a device using a catheter (tube) inserted through a large blood vessel. Cardiac Partners is the  on program in South Jersey to offer transcatheter mitral valve repair (TMVr) with MitraClip™ therapy as a treatment option for patients who suffer from mitral regurgitation.