Patient education: Mitral stenosis in adults (The Basics)

What is mitral stenosis? — Mitral stenosis is a condition in which 1 of the valves in the heart, called the mitral valve, doesn't 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. Then, blood can get backed up in the left atrium, in the blood vessels in the lungs, and in the right side of the heart.

When the valve opening is very narrow, the blood flow from the left atrium to the left ventricle might be less than normal. Blood backs up in the left atrium, the lungs, and the right side of the heart, and not enough blood flows forward.

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. A heart murmur 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, doctors call the condition "heart failure." Heart failure means that blood is not flowing normally through the heart. Heart failure does not mean the heart has actually stopped working. 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. The test done most often to check for mitral stenosis is an echocardiogram (also called an "echo"). This test uses sound waves to create a picture 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. A stress test 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 (also called an "ECG"). This test measures the electrical activity in the heart (figure 3).

Some people with mitral stenosis will also have a chest X-ray. A chest X-ray 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 your mitral stenosis is. If you have mild mitral stenosis or no symptoms, you might not need any treatment. But your doctor will follow you to see 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 – For this procedure, a doctor inflates a balloon in the narrowed mitral valve to try to open it.

●Surgery – Doctors can do different types of surgery to treat mitral stenosis. One type involves opening up the narrowed mitral valve. Another type 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 the mitral stenosis.

Can I play sports? — It depends on your mitral stenosis 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? — No. 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, only people with certain heart conditions need antibiotics in these situations. 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. But most people with mitral stenosis do not need antibiotics in these situations.

What if I want to get pregnant? — If you 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 your mitral stenosis before you get pregnant.

More on this topic

Patient education: Heart murmurs (The Basics)
Patient education: Echocardiogram (The Basics)
Patient education: ECG and stress test (The Basics)
Patient education: Prosthetic valves (The Basics)
Patient education: Atrial fibrillation (The Basics)
Patient education: Coughing up blood (The Basics)
Patient education: Pulmonary hypertension (The Basics)
Patient education: Heart failure (The Basics)
Patient education: Shortness of breath (dyspnea) (The Basics)

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