MITRAL STENOSIS

Mitral stenosis is a heart valve disorder that involves the mitral valve. This valve separates the upper and lower chambers on the left side of the heart. Stenosis refers to a condition in which the valve does not open fully, restricting blood flow.

Blood that flows between different chambers of your heart must flow through a valve. The valve between the two chambers on the left side of your heart is called the mitral valve. It opens up enough so that blood can flow from one chamber of your heart (left atria) to the next chamber (left ventricle). It then closes, keeping blood from flowing backwards.

Mitral stenosis refers to when the valve cannot open as wide. As a result, less blood flows to the body. The upper heart chamber swells as pressure builds up. Blood may flow back into the lungs. Fluid then collects in the lung tissue (pulmonary edema), making it hard to breathe.

Causes of Mitral Stenosis


In adults, mitral stenosis occurs most often in those who have had rheumatic fever . The valve problems develop 5 - 10 years after the rheumatic fever. Rheumatic fever has come down in India, so mitral stenosis is also less common.

Only rarely do other factors cause mitral stenosis in adults. These include calcium deposits forming around the mitral valve, radiation treatment to the chest, and some medications.

Children may be born with mitral stenosis (congenital) or other birth defects involving the heart that cause mitral stenosis. Often, there are other heart defects present, along with the mitral stenosis.

Mitral stenosis may run in families.

Symptoms

In adults there may be no symptoms. Symptoms may, however, appear or get worse with exercise or any activity that raises the heart rate. In adults, symptoms usually develop between ages 20 - 50.

Symptoms may begin with an episode of atrial fibrillation, or may be triggered by pregnancy or other stress on the body, such as infection in the heart or lungs, or other heart disorders.

Symptoms may include:

• Chest discomfort (rare)
  • Increases with activity, decreases with rest
  • Radiates to the arm, neck, jaw, or other areas
  • Tight, crushing, pressure, squeezing, constricting
• Cough, possibly bloody (hemoptysis)
• Difficulty breathing during or after exercise or when lying flat; may wake up with difficulty breathing
• Fatigue, becoming tired easily
• Frequent respiratory infections such as bronchitis
• Sensation of feeling the heart beat (palpitations)
• Swelling of feet or ankles

In infants and children, symptoms may be present from birth (congenital), and almost always develop within the first 2 years of life. Symptoms include:

• Bluish discoloration of the skin or mucus membranes (cyanosis)
• Poor growth
• Shortness of breath

Signs and tests

The doctor will listen to the heart and lungs with a stethoscope. A distinctive murmur, snap, or other abnormal heart sound may be heard. The typical murmur is a rumbling sound that is heard over the heart during the resting phase of the heartbeat. The sound gets louder just before the heart begins to contract.

The exam may also reveal an irregular heartbeat or lung congestion. Blood pressure is usually normal.

Narrowing or obstruction of the valve or swelling of the upper heart chambers may show on:

• Chest x-ray
• ECG
• Echocardiogram
• Doppler ultrasound
• Cardiac catheterization
• MRI of the heart
• Transesophageal echocardiogram (TEE)

Treatment - Timing Is Everything

With mitral stenosis (MS), the mitral valve (the valve that lies in between the heart's two left chambers) becomes thickened and immobile, failing to open completely and impeding blood flow. Since MS is fundamentally a mechanical problem, the ultimate solution must be a surgical one -- that is, some intervention to relieve the obstruction.

If you have MS, the most critical question is deciding whether to perform surgery and when to perform it.
The timing of mitral valve surgery is very important. MS usually gets worse very slowly, and people with MS can remain entirely without symptoms for many years. You may think it's better just to get the procedure over with, but performing the surgery too early can expose you to unnecessary risk.
On the other hand, waiting too long to perform surgery can lead to irreversible heart damage, so that mitral valve surgery will no longer be effective. This can be a fatal mistake.
Deciding on the appropriate time to perform mitral valve surgery largely depends on your symptoms, as well as measurements of how well your mitral valve opens and the pressure within your pulmonary artery. These measurements can be done with an echocardiogram.
It is very important to pay close attention to any shortness of breath, fatigue, and changes in your ability to exert yourself. Your doctor will help by asking the right questions. (How many steps can you climb before becoming short of breath? How long does it take you to walk one kilometer? Do you cough when you exert yourself? Etc.)

Deciding When the Time Is Right for You

With these considerations, let's look at some general "rules" for deciding when it's time for surgery.

• If you have no symptoms at all and your MS is considered mild, the main decision you and your doctor will make is how often you should have repeat evaluations. Depending on your assessment, echocardiograms performed every year or 2 to 3 years may be necessary. If you experience shortness of breath or fatigue in between checks, go for a sooner-than-scheduled re-evaluation.
• If you have mild MS and mild symptoms, your doctor may ask you to have an exercise echocardiogram - that is, a stress test during which an echocardiogram is performed. This test allows the doctor to estimate your pulmonary artery pressure during exercise.
• If you develop elevated pulmonary artery pressure during exercise, your doctor may refer you for surgery. However, in general, patients with mild MS are referred for mitral valve repair only if they are candidates for percutaneous mitral balloon valvulotomy (PMBV), a relatively non-invasive mitral valve repair procedure.
• If you have moderate to severe MS and also have symptoms, and your pulmonary artery pressure is elevated either at rest or during exercise, you should have surgery. In this case you will probably be referred for PMBV if that procedure is feasible. If it is not feasible, you will be referred for another mitral stenosis surgery -- an open procedure to either repair or replace your mitral valve.
• If you have severe MS and very significant symptoms, the issue is no longer whether the MS is severe enough to perform surgery, but whether the MS has progressed beyond the point where surgery would be of any help. Making this decision can be relatively difficult, and it often involves a full cardiac catherization and close consultation and discussion between you, your cardiologist and the cardiac surgeon.

Can Drugs Help Mitral Stenosis?

Definitive therapy requires physically relieving the obstruction, but medical therapy can offer some advantages.
Diuretics (water pills), usually the more powerful diuretics such as Lasix  can help with shortness of breath or with fluid retention.
Using drugs to prevent rheumatic fever are important, especially in younger patients, if the MS is due to rheumatic heart disease.
In general, using drugs that help prevent endocarditis is no longer recommended for people with MS.
Since atrial fibrillation tends to cause worse symptoms in patients with MS than in patients without it, aggressive treatment to control symptoms should be used.

Preventing Blood Clots

People with MS have an increased risk of thromboembolism (blood clots within blood vessels or the heart that break off and cause tissue damage such as stroke). In MS, the thrombus tends to form in the left atrium. The risk of thromboembolism is greatly increased if atrial fibrillation is present.
For this reason, anticoagulation with Warfarin(Coumadin) is recommended in patients with MS who have any of the following:

• a history of a prior thromboembolic event, especially stroke
• left atrial thrombus (which can be detected by echocardiogram
• atrial fibrillation
• according to some experts, a greatly enlarged left atrium (also detected by echocardiogram)

Expectations (prognosis)

The outcome varies. The disorder may be mild, without symptoms, or may be more severe and eventually disabling. Complications may be severe or life threatening. Mitral stenosis is usually controllable with treatment and improved with valvuloplasty or surgery.

Complications

• Atrial fibrillation and atrial flutter
• Blood clots to the brain (stroke), intestines, kidneys, or other areas
• Heart failure
• Pulmonary edema
• Pulmonary hypertension

Prevention

Follow the doctors recommended treatment for conditions that may cause valve disease. Treat strep infections promptly to prevent rheumatic fever. Tell your doctor if you have a family history of congenital heart diseases.

Mitral stenosis itself often cannot be prevented, but complications can be prevented. Inform your health care provider of your heart valve disease before you receive any medical treatment.

Please Note;

Call your doctor if:

• You have symptoms of mitral stenosis
• You have mitral stenosis and symptoms do not improve with treatment, or new symptoms appear