Definition

Mitral stenosis is a narrowing of the mitral valve in the heart. The mitral valve is in the left side of the heart between the upper and lower chambers of the heart. The valve normally keeps blood flowing in the right direction from the upper to the lower chambers.

This problem makes it hard for blood to move from the upper and lower chambers. This means there is less blood for the lower chamber to pump out to the body. The blood can also back up in the upper chamber and push back into the lungs.

Mitral Valve Stenosis

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Causes

The most common cause of mitral stenosis is rheumatic fever. This infection may happen after strep throat or scarlet fever. It can scar the heart valves. Mitral stenosis may develop 5 to 10 years after infection.

Less common causes are:

• Structural problems that are present at birth
• Blood clots
• Tumors
• Infective endocarditis
• Growth that block blood flow through the mitral valve

Risk Factors

The risk of this problem is higher in children who have rheumatic fever. Other things that may raise the risk are:

• Being born with mitral valve problems
• Having other health problems that affect blood flow in the heart

Symptoms

Problems may be:

• Difficulty breathing, especially during exercise and when lying flat
• Waking up short of breath in the middle of the night
• Tiredness
• Fast heartbeat
• Coughing up blood
• Swelling of the legs or feet
• Lightheadedness and fainting
• Chest pain (rare)

Diagnosis

The doctor will ask about your child’s symptoms and health history. A physical exam will be done.

Images may be taken of your child's heart. This can be done with:

• Echocardiogram
• Transesophageal echocardiogram
• Chest x-ray
• Cardiac catheterization

Your child's heart function may be tested. This can be done with:

• Electrocardiogram (EKG)
• Stress test

Treatment

Treatment for mild stenosis may not be needed right away. The child may be monitored for changes.

Children who do need treatment may be given medicines to:

• Improve heart function
• Remove excess fluid from the body

Some children may need surgery to prevent heart damage. Choices are:

• Mitral valvulotomy to allow the mitral valve to open wider
• Balloon valvuloplasty to stretch the surrounding tissue by inflating a balloon in the mitral valve
• Mitral valve replacement to put a mechanical or tissue valve in the place of the damaged valve

Prevention

The risk of this problem may be lowered by diagnosing and treating strep throat infections right away.