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Mitral Valve Disorders

What are mitral valve disorders?
What are the symptoms of mitral valve disorders?
What causes mitral valve disorders?
How are mitral valve disorders diagnosed?
How can mitral valve disorders be treated?

What are mitral valve disorders?

The mitral valve is one of your heart's four valves; it controls the flow of blood between the atrium (the upper chamber) and the ventricle (the lower chamber) on your heart's left side. A valve is several little flaps of tissue that open and close each time your heart beats, sending blood in the correct direction—in the case of your mitral valve, out of your left atrium and into your left ventricle. When it's working properly, the flaps of the mitral valve open to allow the atrium to pump blood into the ventricle, then they close to keep blood from flowing back up to the atrium while the ventricle propels blood out to body.

There are several problems that can affect the function of your mitral valve:

  • Mitral valve prolapse (MVP), also called floppy valve or Barlow's syndrome, means the flaps of the valve don't form a tight seal, as they should. Instead, they flop or bulge backward into the atrium. ("Prolapse" comes from Latin words meaning "to fall out.")
  • Mitral valve regurgitation, also called mitral valve insufficiency, means your mitral valve is leaky and allows blood to flow backward into the left atrium. ("Regurgitation" comes from Latin words meaning "to engulf again.") MVP often, though not always, results in leakage in your mitral valve, but a leaky mitral valve can be caused by other factors as well.
  • Mitral valve stenosis means the flaps of the valve are thickened, stiffened or stick together and are thus unable to open completely; this partially blocks the flow of blood from the atrium to the ventricle. ("Stenosis" comes from a Latin word meaning "to make narrow.")

Some people with mitral valve problems experience no symptoms, but if the condition is not treated it can result in serious complications, including congestive heart failure or an arrhythmia (irregular heartbeat). It is estimated that between 2 million and 4 million people in the U.S. have some form of mitral valve damage, with mitral valve prolapse being the most common such condition; about 18,000 people a year have surgery to repair a damaged mitral valve.

What are the symptoms of mitral valve disorders?

Symptoms of a disease are indications that can be detected by the patient, such as pain or fatigue (while signs are indications that can be detected by a doctor, such as the results of a blood test or an X-ray). Some people with mitral valve conditions experience no symptoms. If symptoms do occur, they often come on gradually.

They are similar for the various different mitral valve conditions and include a cough; shortness of breath, especially if you are exercising or lying on your back; fatigue; and lightheadedness. Some individuals with mitral valve problems also feel chest pain or tightness, while others may have an irregular or unusually fast heartbeat.

What causes mitral valve disorders?

The causes of the various different mitral valve conditions vary, as follows:

  • There is no known cause of mitral valve prolapse (MVP), though it is known to run in some families and to be associated with certain other conditions, such as scoliosis (curvature of the spine).
  • Mitral valve regurgitation may be a result of MVP, but it can also be caused by various other heart conditions, including endocarditis, an inflammation or infection of the valve; a heart attack, also known as a myocardial infarction; or rheumatic fever. In fact, rheumatic fever used to be a common cause of both mitral valve regurgitation and mitral valve stenosis. Rheumatic fever is an inflammatory disease often triggered by the strep bacterium; however, antibiotics have made it much less common in the U.S. than in the past, so this cause of mitral valve disease is seen mostly in individuals who had rheumatic fever before antibiotics were widely available or who are from countries where rheumatic fever is still common.
  • Most cases of mitral valve stenosis are caused by rheumatic fever, so the rarity of that condition today means mitral valve stenosis is much less common than it used to be. There are a few other causes of mitral valve stenosis, however, including congenital heart defects, radiation treatment for cancer, and some tumors.

The prevalence of all these conditions increases with age, and they are more likely to affect men than women.

How are mitral valve disorders diagnosed?

Image of EKG If a damaged mitral valve is symptomless, it can sometimes be identified during a routine physical exam. For example, if your doctor detects signs such as a heart murmur, it may lead to a suspicion of mitral valve disease.

If such signs—or the presence of symptoms—cause your doctor to suspect that you may have a diseased mitral valve, certain diagnostic tests will likely be conducted. They may include an electrocardiogram (also referred to as an ECG or EKG), which measures and records your heart's electrical activity; an echocardiogram (an ultrasound image of your chest); a chest X-ray; a stress test; an MRI of your heart; or an angiogram (also referred to as cardiac catheterization), which uses opaque dye to image your cardiovascular system.

How can mitral valve disorders be treated?

There are no current medications that can cure a damaged mitral valve. However, in cases of mild mitral valve disease, medications that lower your blood pressure or reduce the likelihood of blood clots may relieve some symptoms and delay the development of complications. Lifestyle changes (such as not smoking and staying active) can also lessen your symptoms and delay the development of complications.

Often, however, the best course may be surgical repair of the diseased mitral valve—even if it is not yet causing symptoms. With current surgical techniques perfected by the cardiac surgeons at Dartmouth-Hitchcock, mitral valves can almost always be repaired, eliminating the need for an artificial valve. In some cases, however, replacement of a damaged mitral valve may be indicated. While there are risks to surgery, which need to be balanced against the risks that your valvular disease will progress, surgery usually fixes the damaged valve, prevents further damage to your heart and relieves all symptoms.

Page reviewed on: Jun 26, 2015

Page reviewed by: Jock McCullough, MD

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