What is mitral valve stenosis?

Mitral valve stenosis (sometimes called mitral stenosis) is a disease that causes narrowing or blockage of the mitral valve inside your heart. Over time, this condition can cause heart rhythm problems, a higher risk of stroke, and may lead to heart failure and death.

Mitral valve stenosis means blood traveling between the chambers on the left side of your heart can’t flow as easily. This condition is almost always the result of an allergic or immune reaction to a bacterial infection, but children can also have this when they're born. It can also happen in the elderly.

Who does mitral stenosis affect?

Mitral stenosis is much more likely to happen in women than in men. In developed countries, people in their 50s and 60s make up the majority of mitral stenosis cases. In developing countries, it is a more common diagnosis in younger adults. When it occurs in infants and children, most cases are found before the age of 2. It may also run in families, increasing the risk of having it if one of your relatives also has it.

How common is mitral valve stenosis?

Mitral stenosis is an uncommon disease, especially in developed countries. It affects about 1 out of every 100,000 people in the U.S. It’s more common in developing countries, especially when there’s limited access to antibiotics and medical care.

What causes mitral stenosis?

The mitral valve is on the left side of your heart and it controls blood flow from the left atrium (upper chamber) to the left ventricle (lower chamber). It's the first valve that blood has to pass through after traveling through your lungs to collect oxygen. It’s also the only valve in your heart that should have two flaps (called leaflets) instead of three.

There are a few different causes for mitral stenosis:

• Damage from infections: Rheumatic fever is the most common cause of mitral stenosis. Often called rheumatic mitral stenosis, this happens when your immune system damages the valve while fighting an untreated bacterial infection. Rheumatic mitral stenosis becomes worse over time.
  Bacteria that cause rheumatic mitral stenosis are the same ones that cause strep throat and scarlet fever. Rheumatic mitral stenosis is most common in middle-aged individuals, and the diagnosis is usually years or even decades after the infection happened. That's because it may take years or decades before the damage to your heart valves causes symptoms or appears on a medical exam.
• Wear and tear due to age: This type of stenosis is more likely with advancing age and results from calcium buildup on the valve. However, most people with age-related mitral stenosis have only mild or moderate narrowing and may not need treatment.
• Present at birth. Congenital (meaning you have it when you’re born) mitral stenosis is usually detected before the age of 2. This kind of stenosis can range from mild to severe. If not treated, children with severe mitral stenosis typically don't survive past age 5.

What are the symptoms of mitral stenosis?

If you have mild or moderate stenosis, you may not have any symptoms. Many women who have mitral stenosis don’t know it until they develop symptoms while pregnant because their heart also provides blood to a fetus. The symptoms most likely to happen are:

• Shortness of breath. This is the most common symptom. It usually happens during physical activity and exercise but can also happen while lying down.
• Fatigue. More than being tired, this describes when you feel exhausted to the point that it interferes with your normal activities.
• Bronchitis. Infections usually cause this, and if you have mitral stenosis, you may get these infections more often.
• Heart palpitations (where you become unpleasantly aware of your own heartbeat). This often happens when mitral stenosis puts more pressure on the upper left chamber of your heart, causing an irregular heart rhythm called atrial fibrillation.
• Stroke. When the upper chambers of your heart are under increased pressure, a clot can form because of the reduced blood flow. This clot can then travel from your heart to your brain, where it can get in a smaller blood vessel and cause a stroke.
• Coughing blood. This sometimes happens when the limited blood flow puts pressure not just on the upper chamber of your heart but also in the veins in your lungs.
• Hoarseness. One of the nerves that control your vocal cords runs next to your heart. Increased pressure in the upper chamber of your heart can put pressure on this nerve. Just as your leg can fall asleep if one of its nerves is pressed on for too long, your voice may give out if this nerve is under enough pressure.
• Swelling in your abdomen, ankles or feet. This happens when your heart is struggling to pump effectively, causing fluid to build up.

Children who are born with mitral stenosis often have these symptoms:

• Trouble feeding or sweating while feeding. This symptom is one of the most common indicators of mitral stenosis in infants.
• Cough. This may also include wheezing or struggling to breathe.
• Slowed growth. This means that the child’s height, weight and other indicators are lower than expected for their age.
• Frequent respiratory infections.
• Shortness of breath. This is especially common and in older children, it may cause them to tire out easily when they’re active.

How fast does mitral stenosis progress?

It can take years or even decades before mitral stenosis symptoms develop, especially when it’s caused by rheumatic fever. This means many people don’t develop mitral stenosis for 20 to 40 years after they first had rheumatic fever.

Once a person develops symptoms, the progression of the disease usually speeds up. About 80% of people don’t survive more than 10 years from when their symptoms first appeared. For people who’ve developed high blood pressure in their lungs because of mitral stenosis, that survival time is around three years. Heart failure is common in advanced cases.

For children born with mitral stenosis, the outlook strongly depends on the severity of their case. Many people born with mitral stenosis may need screening for related heart problems for the rest of their lives.

How is mitral stenosis diagnosed?

Your primary care provider may detect symptoms of mitral stenosis during a regular checkup and refer you to a specialist. A cardiologist will usually do one or more of the following tests to diagnose your case and determine its severity:

• Physical exam. One of the easiest signs of mitral stenosis for a healthcare provider to detect is a heart murmur. Your provider can hear usually hear a murmur when using a stethoscope to listen to your heart and breathing during a routine physical. More severe cases can cause more than one sound as part of the murmur, which can help your provider determine the severity of your case.
• Echocardiogram. This test uses ultrasound waves to give healthcare providers a picture of the inside of your heart. It is the most common test used to diagnose mitral stenosis.
• Electrocardiogram (ECG or EKG). This measures the electrical activity of your heart using sensors attached to the skin of your chest. While an electrocardiogram can easily detect heart rhythm problems connected to mitral stenosis, it’s usually not enough for a complete diagnosis.
• Chest X-ray. Using X-rays to see inside your body, a healthcare provider can look for telltale changes in the shape or structure of your heart that mitral stenosis is known to cause.
• Cardiac catheterization. Using a device inserted into one of your blood vessels and threaded up to your heart, a specialist can measure pressures within your heart and determine if you have mitral stenosis.

Can mitral stenosis be cured?

Mitral stenosis can't be cured, but it's possible to manage it. Some treatments, especially valve repair or replacement, can stop or reduce your symptoms for years. Other treatments, such as medication, can also help by preventing complications.

Some of the possible treatments include:

• Medication: Several different types of medicine can treat mitral stenosis. Some of the drugs used include those that treat high blood pressure, symptoms of heart failure (especially swelling from too much fluid), manage fast heart rhythms and blood thinners (to prevent stroke). Your provider may also prescribe a long-term course of antibiotics to prevent heart valve damage.
• Catheter-based procedures. These access your heart from inside your body by inserting a device into an artery elsewhere on your body. The catheter is then threaded up to your heart and used to repair or replace the valve.
  • Balloon valvotomy: Sometimes called valvuloplasty, this procedure involves a catheter with a balloon attached. Once it reaches your mitral valve, inflating the balloon can widen the narrowed area.
  • Valve replacement: In some cases, it's possible to replace a valve using a catheter-based procedure. This is called transcatheter mitral valve replacement, or TMVR.
• Surgery: A surgeon can use many different methods, including minimally invasive surgery or robotically assisted surgery. Depending on your case and your needs, your surgeon may recommend either repairing the valve or replacing it altogether.

What types of replacement valves are there for mitral stenosis, and why choose one over the others?

• Animal valves: Made from animal tissue, usually taken from pigs or cows, these are also a good option if you want to avoid taking blood-thinning medications. They last about 15 to 20 years.
• Mechanical valve: These valves are often composed of pyrolytic carbon (which is similar to diamonds but with a different structure). These are highly durable and easily accepted by your body. Some of these valves also have polyester knit fabric around their edges. If you have one of these valves placed, you will need to take blood thinners for the rest of your life to prevent problems like stroke. These valves may last for many years.
• Bioprosthetic valve: These valves often combine animal tissue and artificial parts. The animal tissue is usually attached to a metal frame, which keeps the valve in place. These valves typically last about 15 to 20 years. Animal tissues are used for the leaflets or moving parts and — unlike mechanical valves — are resistant to developing blood clots on top of them.

How long does it take to recover from this treatment?

Recovery time for mitral valve stenosis repair or replacement procedures depends on the method. Surgical methods take the longest. You may need to stay in the hospital for days, and it may be weeks before you recover fully.

Methods that use a catheter-based approach have much faster recovery times. Most patients can go home either the same day or the next day and recover fully in days or a few weeks.

What else can I do to manage mitral stenosis?

Your healthcare provider can help guide you through what you can do to manage mitral stenosis. Because many patients don’t have symptoms, it’s common for your healthcare provider to recommend follow-up monitoring and testing every so often.

For those with severe or advanced mitral stenosis, your healthcare provider may tell you to limit how active you are to reduce the strain on your heart. It’s also common for your healthcare provider to recommend a low-salt or low-sodium diet if you have mitral stenosis.

People with mitral stenosis, either mild or severe, may also need to go on medication to prevent complications like stroke, heart failure, high blood pressure, or drugs to slow their heartbeat or to prevent it from going fast. In addition, some people may need to take medication for the rest of their life, especially people who've had their mitral valve replaced. Your healthcare provider can tell you about the medications options, as well as how to take them and for how long.

Can mitral stenosis be prevented?

Most cases of mitral stenosis happen because of unrecognized — and therefore untreated — bacterial infections. That means treating those infections can prevent most cases of mitral stenosis. Don’t wait to treat a bacterial infection like strep throat or scarlet fever, and follow your healthcare provider’s instructions closely. Take any prescribed antibiotics and other medications according to the instructions, not just until you feel better.

Mitral stenosis due to age usually can’t be prevented. However, you may be able to delay when it happens by exercising regularly, maintaining a healthy weight, eating a healthy diet and getting an annual checkup.

Unfortunately, mitral stenosis that you're born with isn't preventable.

What is the outlook for mitral stenosis?

• Untreated: Once mitral stenosis causes symptoms, it’s important to get it treated sooner rather than later. Four out of five people who don’t go treated die within 10 years of when their symptoms started. If their symptoms include high blood pressure in your lungs, the survival time is less than three years.
• Delayed treatment: Waiting to treat mitral stenosis once symptoms start is usually not recommended. By the time symptoms begin, the problem is often past the mild stage and is often moderate or severe. In addition, certain problems that happen with mitral stenosis can cause damage to your heart that can’t be repaired or reversed.
• Timely or early treatment: The best outcomes from mitral valve stenosis happen with early detection and timely treatment. Because mitral valve stenosis usually causes a heart murmur, your healthcare provider can often catch it when they listen to your heart during an annual physical exam or checkup. This can help detect and treat it before it becomes severe or advanced.

When should I call my healthcare provider?

If you develop the symptoms of mitral stenosis, especially ones that disrupt your life, you should call your healthcare provider or schedule an appointment.

When should I go to the ER?

After starting a new medication, you should go to the ER if any of the following happen:

• If you have an unexpected side effect from your medicine. Your healthcare provider can tell you which side effects need immediate medical attention.
• If you faint or pass out for any reason.
• If you are on blood thinners and suffer a fall. Blood thinners significantly increase the risk of internal bleeding — especially after a fall or other injury — which can be deadly.

After a surgery or catheter procedure, you should go to the ER if any of the following happen:

• If your incision site becomes red, swollen or hot to the touch. These are signs of an infection that needs immediate treatment.
• If you have any serious aortic stenosis symptoms, including shortness of breath, chest pain, heart palpitations, or if you faint.
• If you are on blood thinners and suffer a fall, for the same reasons listed above.