What is mitral stenosis?

Mitral stenosis, or mitral valve stenosis, is a narrowing of the mitral valve. One of your heart’s four valves, the mitral valve controls blood flow between the left atrium (upper chamber) and left ventricle (lower chamber) of the heart. Stenosis can restrict the amount of blood flowing through the heart to the rest of the body.

Your mitral valve normally opens to allow blood to flow, then closes to prevent it from flowing back. When the mitral valve narrows, blood flow is limited. As a result, blood can get trapped in your left atrium, putting pressure on the blood vessels that bring oxygen-rich blood from your lungs to your heart. Over time, this pressure can cause your heart’s upper chambers to get larger and allow fluid to build up in your lungs.

a visual depiction of mitral valve stenosis

Mitral stenosis symptoms

Mitral stenosis typically does not cause symptoms unless it is severe. You may not know you have it until your doctor hears a heart murmur when listening to your heart at a routine check-up.

However, you might experience symptoms when your heart is under stress, for example, during pregnancy or an infection.

Symptoms of mitral stenosis may include:

  • Breathing difficulties during or after activity or when lying down
  • Chest pain or discomfort with activity that radiates to the arm, neck, jaw or other parts of the body
  • Coughing that may be bloody
  • Fainting
  • Feeling dizzy or lightheaded
  • Feeling very tired
  • Flushed cheeks that appear purple (mitral facies)
  • Frequent respiratory infections
  • Heart palpitations
  • Shortness of breath when resting
  • Swollen ankles or feet

Mitral stenosis can also exist at birth. In babies and children with the condition, symptoms usually appear by age 2 and may include:

  • Coughing
  • Problems gaining weight, possibly due to feeding difficulties
  • Shortness of breath
  • Slowed growth

When to see a doctor

See your doctor if you have symptoms of mitral stenosis, particularly if you have a bloody cough, which could suggest severe narrowing of the valve. Always call 911 if you experience chest pain that radiates to your neck, back or jaw, shortness of breath and dizziness, or lightheadedness, as these could be signs of a heart attack.

Because the condition often causes no symptoms, having regular checkups with your primary care doctor allows them to identify heart murmurs and other signs early.

Causes of mitral stenosis

Mitral stenosis can be caused by a birth defect. The most common cause in adults is rheumatic fever, an infection that can develop after untreated strep throat or other infections. Mitral valve symptoms may not appear until decades after an illness.

Narrowing of the valve can also be caused by a buildup of calcium, which is more common as you get older. Other possible, but less common, causes include:

  • Endocarditis, an infection of the heart and heart valves
  • Radiation treatments to the chest
  • Rheumatoid arthritis
  • Systemic lupus erythematosus
  • Whipple disease
  • Carcinoid, a slow-growing tumor

Mitral stenosis risk factors

Having a condition linked to mitral stenosis can increase your risk. However, it’s becoming less common in the United States thanks to better infection treatments that have lowered rates of rheumatic fever, the leading risk factor for mitral stenosis.

Mitral stenosis becomes more common with age. Older adults are more likely to have calcium buildup on their valves, and they may have had an infection early in life before the widespread use of antibiotics. Mitral stenosis is also common in parts of the world where antibiotic use is lower than it is in the US.

Additional risk factors include:

  • Genetics: Mitral stenosis may run in families and can be linked to genetics.
  • Sex: Mitral stenosis caused by rheumatic fever is more common in women than men.
patient consulting with doctor about mitral valve stenosis risk factors

Complications

Left untreated, mitral stenosis can lead to serious complications. Reduced blood flow through your valve can mean less oxygen-rich blood is pumped around your body. As blood builds up in your left atrium, this can increase pressure. Blood clots can form, which may break off and travel to other parts of your body.

Possible complications include:

  • Arrhythmias: Problems with the mitral valve can cause atrial fibrillation or atrial flutter.
  • Heart failure: The added strain on the heart may reduce its ability to pump enough blood for the rest of your body, leading to heart failure.
  • Pulmonary edema: As blood builds up in your left atrium, fluid can collect in your lungs. This is called pulmonary edema.
  • Pulmonary hypertension: Pressure buildup can cause high blood pressure in the lungs.
  • Stroke: A blood clot blocking blood flow to your brain can cause an ischemic stroke .

Diagnosing mitral stenosis

The diagnostic process for mitral stenosis often begins when your doctor hears a heart murmur during a physical exam. Many lifestyle factors and conditions can cause a murmur, so they will likely try to determine its cause.

You may need various tests to determine whether you have mitral stenosis or another condition. Your doctor may refer you to a cardiologist.

Mitral stenosis treatment

If your doctor diagnoses you with mitral stenosis, they may grade it from 1 to 4. In grade 1, the valve has minimal narrowing and a small amount of calcium buildup. By grade 4, the most severe, the valve has become very thick and calcified.

If your mitral stenosis is mild or does not cause bothersome symptoms, you may not need treatment. Your doctor will usually recommend annual checkups and regular tests to ensure your condition does not get worse, and they may recommend antibiotics before certain dental or medical procedures to prevent an infection like endocarditis from damaging your heart.

For more severe grades of mitral stenosis, your doctor may recommend medication, nonsurgical procedures or surgery.

Medication

Your doctor may prescribe various medications, depending on your symptoms and how severe they are. Medication can reduce your risk of complications, such as blood clots, which can cause heart attacks or strokes. Always tell your doctor if you experience any side effects.

Medications to treat symptoms include:

  • Antiarrhythmic medicine: These can treat abnormal heart rhythms caused by mitral stenosis.
  • Beta blockers: These drugs slow your heart rate and reduce blood pressure, lowering your risk of heart problems.
  • Blood thinners: These prevent blood clots that could cause a stroke.
  • Calcium channel blockers: These prevent calcium from entering the muscle cells of your heart and blood vessels, allowing them to relax.
  • Diuretics: These reduce stress on your heart by removing excess fluid from your body.

Locations for mitral stenosis

Find the experienced, nationally recognized care you need for mitral stenosis and other heart valve diseases at Baylor Scott & White. We can help you find care in North and Central Texas at the location that meets your needs.

Frequently asked questions

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