Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link
Quick Facts

Mitral Stenosis


The Manual's Editorial Staff

Last full review/revision Feb 2021| Content last modified Feb 2021
Get the full details
Topic Resources

What is mitral stenosis?

Four heart valves control how blood flows in and out of your heart. The valves are like one-way doors that keep blood flowing in the right direction.

Your mitral valve separates your left atrium and left ventricle. This valve opens to let blood from your lungs out of your left atrium and into the left ventricle. The valve closes to keep blood from running back into your left atrium.

Mitral stenosis is when the mitral valve doesn't open all the way so it's hard for blood from your lungs to get out of the left atrium. Blood pressure in your left atrium and your lungs builds up.

If you have mitral stenosis, pregnancy can make heart failure develop quickly.

What causes mitral stenosis?

What are symptoms of mitral stenosis?

Mild mitral stenosis doesn't usually cause symptoms.

  • Get tired easily

  • Feel short of breath

  • Have swelling in your legs

Atrial fibrillation may cause:

  • Palpitations (feeling your heart pounding, fluttering, racing, or skipping beats)

  • Shortness of breath

Once symptoms start, people become severely disabled in about 7 to 9 years. Children born with mitral stenosis often don’t live more than 2 years unless they have surgery.

How can doctors tell if I have mitral stenosis?

How do doctors treat mitral stenosis?

If you don't have symptoms, you don't need treatment.

If you have symptoms, doctors will treat you with medicines to:

  • Make you urinate more and lower the blood pressure in your lungs

  • Control your heart rate

  • Prevent blood clots

If the medicines don't control the symptoms enough, the valve may be repaired or replaced.

When possible, doctors try to repair the valve, a procedure called a valvuloplasty. During valvuloplasty, the doctor inserts a thin, hollow tube (catheter) through a vein or artery into your heart. The doctor inflates a balloon on the tip of the catheter. The balloon pushes the valve open. Sometimes doctors repair the valve during heart surgery.

If your valve cannot be repaired, it can be replaced with:

  • A plastic, mechanical valve

  • A valve from a pig or cow heart (bioprosthetic valve)

If you get a mechanical valve, you'll need to take blood-thinning medicine for the rest of your life, but the valve may last several decades. If you get a bioprosthetic valve, you'll need to take the blood-thinning medicine for only a few months, but the valve will last only 10 to 12 years.

People with damaged or replaced valves sometimes need antibiotics to prevent heart valve infection, such as when they:

  • Get dental work

  • Have certain medical procedures

Others also read
Test your knowledge
Starting Solid Foods in Infants
The time to start solid food depends on the infant’s needs and readiness. However, starting solid foods earlier than 4 months of age or later than 6 months of age may be associated with an increased risk of which of the following?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID