What is mitral stenosis?

Mitral stenosis is a narrowing of the opening of the mitral valve. The mitral valve is one of the four heart valves. These valves control the flow of blood through the heart. Mitral stenosis limits the flow of blood through the mitral valve and causes the heart to work harder.

How does it occur?

Mitral stenosis is almost always due to scarring of the valve from rheumatic fever. It is four times more common in women than in men.

What are the symptoms?

Symptoms appear gradually, sometimes over years. Symptoms usually begin when your heart is forced to pump blood more quickly or forcefully by things such as:

• strenuous activity

• fever

• emotions, such as fear, that make your heart beat faster.

Symptoms may include:

• chest pain

• fatigue

• decreased ability to exercise

• shortness of breath

• loss of stamina

• difficulty breathing, sometimes during the night or when you are lying flat

• palpitations (awareness of your heartbeat)

• long-lasting cough or coughing up blood.

How is it diagnosed?

Your health care provider will review your symptoms and examine you. Mitral stenosis makes a special sound that your provider can hear through a stethoscope. You may also have the following tests:

• chest x-ray

• electrocardiogram (ECG), a recording of your heart's electrical signals

• echocardiography (an ultrasound scan of the heart).

You may also need:

• heart catheterization: A thin tube (catheter) is passed into one of your blood vessels and into your heart to measure pressure inside the blood vessels and heart.

• angiogram: This procedure is used to examine the inside of your blood vessels. A solution that shows up on x- rays is injected into the catheter and into the blood as it flows through the heart. A series of x-rays are taken to show how the heart valves and heart chambers are working.

How is it treated?

If the narrowed valve is not causing any symptoms, no treatment is required. However, when you have any dental work, including cleaning or any surgery, you should take the antibiotics prescribed by your health care provider. The antibiotics prevent possible infection from bacteria that may be released into the bloodstream during the dental work. Without antibiotics, bacteria tend to collect on the valve and infect it.

When you begin to have mild symptoms, such as less ability to do your usual exercise or swelling of the ankles, you will need treatment. Your health care provider may prescribe a low-salt diet or medicine to help get rid of excess body water (diuretics). If your symptoms worsen over time, then you will need other medicines to help your heart pump more efficiently.

Mitral stenosis can cause abnormal heart rhythms, especially atrial fibrillation. If this occurs, then your health care provider may prescribe digoxin, beta blockers (for example, propranolol or atenolol), or other medicines. If the atrial fibrillation cannot be controlled, then you will need to take a blood thinner (anticoagulant) to prevent a stroke. Otherwise, during atrial fibrillation blood clots could form. These blood clots could cause a stroke.

Your symptoms of heart problems may worsen. For example, you may develop shortness of breath or chest pressure. It may become harder for you to do your normal activities. If this happens, you may need to have the valve opening widened. Sometimes the widening is done with a cardiac catheter. Sometimes it requires open-heart surgery.

As the function of the mitral valve worsens over time, you may need to have the valve replaced. This should be done before your heart is permanently damaged. Because artificial heart valves don't last forever, your doctor won't want to do this until it is necessary. Natural tissue valves (for example, from pigs) tend to wear out in 10 to 15 years. Mechanical valves tend to last longer, but they are more prone to cause blood clots and strokes.

How long will the effects last?

You may have mitral stenosis in a mild form, with few or no symptoms, all of your life. However, it could become severe in a few years. You may go through a long period with no symptoms. Then symptoms may develop fairly rapidly if the narrowing of your valve worsens.

Permanent heart muscle damage can occur if you don't get treatment when your symptoms worsen. See your health care provider regularly so you can get the proper treatment as early as possible.

How can I take care of myself?

Follow the treatment your health care provider prescribes. In addition:

• Stop smoking.

• Get regular checkups.

• With your health care provider's supervision, take antibiotics to prevent infections that could spread to the heart valve if you are having any kind of surgery. This includes dental surgery and minor procedures such as sigmoidoscopy. Also take antibiotics if you are having your teeth cleaned.

• Lose weight if you are overweight. Ask your health care provider to recommend a safe, healthy diet.

• Avoid alcohol if you are taking heart medication.

• Don't drink a lot of beverages that have caffeine. Also try to avoid drugs that contain caffeine.

• Learn ways to reduce or manage stress.

• Avoid taking aspirin if you're taking an anticoagulant (blood-thinning drug).

• Exercise regularly according to your health care provider's advice.

• Talk to your health care provider before you use any other medications, including nonprescription medicines.

• Limit your salt intake if the health care provider suggests a low-salt diet.

• Ask your health care provider about a potassium supplement if you're taking diuretics that cause potassium loss.

• Tell all other health care providers you see about your condition.

How can I help prevent mitral stenosis?

Mitral stenosis is often a result of rheumatic fever, which is caused by the same bacteria that cause strep throat. Have throat cultures done if you have a sore throat. If the results are positive for strep throat, take antibiotics as prescribed by your health care provider.