Patient education: Mitral stenosis in adults (The Basics)

What is mitral stenosis? — 

This is a condition in which 1 of the valves in the heart, called the "mitral valve," does not open fully.

When they work normally, the heart valves do 2 things:

●Open all the way to let blood flow through them

●Keep blood flowing in only 1 direction

The mitral valve keeps blood flowing from the left atrium to the left ventricle (figure 1). In mitral stenosis, the mitral valve does not open fully, so the valve opening is too narrow. This means less blood can flow through. It can cause blood to get backed up in the left atrium, in the blood vessels in the lungs, and in the right side of the heart.

What are the symptoms of mitral stenosis? — 

Early on, most people have no symptoms. They might find out they have mitral stenosis after their doctor or nurse hears a heart murmur on a routine exam. This is an extra sound in the heartbeat that doctors or nurses hear when they listen to the heart with a stethoscope.

When people have symptoms of mitral stenosis, it is called "heart failure." This means blood is not flowing normally through the heart. Heart failure does not mean the heart has actually "failed" or stopped beating. Symptoms can include:

●Trouble breathing – This is the most common symptom. At first, people usually have trouble breathing only during physical activity. But later on, people can have trouble breathing at rest, too.

●Feeling tired

●A severe cough, or coughing up blood or mucus

●Swelling in the legs

Mitral stenosis can also lead to problems such as:

●A heart rhythm problem called "atrial fibrillation"

●Blood clots forming in the heart – If blood clots form in the heart, pieces can break off and travel through the blood vessels to other parts of the body. They can then get stuck in small blood vessels and block them off. This can cause organ damage such as a stroke, which is when part of the brain is damaged.

Is there a test for mitral stenosis? — 

Yes. Doctors usually do an echocardiogram ("echo") to check for mitral stenosis. It uses sound waves to create pictures of the heart as it beats. It shows the size of the heart chambers, how well the heart is pumping, and how well the heart valves are working (figure 2).

Sometimes, people have a test called a "stress test" along with their echo. This measures how well the heart works when it pumps very fast. When a stress test is done with an echo, it's called a "stress echo."

All people with mitral stenosis will have a test called an electrocardiogram ("ECG"). This measures the electrical activity in the heart (figure 3).

Some people with mitral stenosis will also have a chest X-ray. This shows the size and shape of the heart. It can also show changes in the lungs from mitral stenosis or other diseases.

How is mitral stenosis treated? — 

Treatment depends on your symptoms and how severe the mitral stenosis is. If you have mild mitral stenosis or no symptoms, you might not need any treatment. But your doctor will tell you when to schedule follow-up appointments so they can check if your mitral stenosis gets worse or you start to have symptoms.

If your mitral stenosis causes symptoms or is severe, treatment can include:

●A procedure to open your mitral valve – A doctor inserts a balloon into the narrowed mitral valve. Then, they inflate the balloon to try to open the valve.

●Surgery – Doctors can do different types of surgery to treat mitral stenosis. One type involves opening up the narrowed mitral valve. Another involves replacing the narrowed valve with a "prosthetic" valve. This new valve can be made from metal or from tissue from an animal (such as pig or cow) or another person.

●Medicines – A procedure or surgery is the main way to treat mitral stenosis that causes symptoms. But certain medicines can help with symptoms or prevent problems caused by mitral stenosis.

Can I play sports? — 

It depends on your condition and symptoms. You and your doctor should discuss the level of physical activity that is right for you.

Do I need to take antibiotics before I go to the dentist? — 

Probably not. In the past, doctors recommended that people with mitral stenosis take antibiotics before going to the dentist or having certain medical or dental procedures. But now, most people with mitral stenosis do not need antibiotics in these situations. Doctors only recommend this for people with certain heart conditions. For example, people with a prosthetic (replacement) valve need to take antibiotics before some procedures. The same is true for people who have had a valve infection in the past.

What if I want to get pregnant? — 

Talk with your doctor before you start trying. Pregnancy can worsen or trigger symptoms of mitral stenosis. Because of this, your doctor might recommend treating the mitral stenosis before you get pregnant.

More on this topic

Patient education: Heart murmurs (The Basics)
Patient education: Heart failure (The Basics)
Patient education: Atrial fibrillation (The Basics)
Patient education: Echocardiogram (The Basics)
Patient education: ECG and stress test (The Basics)
Patient education: Prosthetic valves (The Basics)

Patient education: Heart failure (Beyond the Basics)
Patient education: Atrial fibrillation (Beyond the Basics)