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What is mitral valve stenosis?

Valvular heart disease occurs when the valves that control blood flow in the heart don’t work properly. Valvular conditions can be congenital (present at birth) or can be acquired later in life. Valvular stenosis occurs over time as the opening in a valve narrows due to a collection of calcium deposits. When that happens, the heart cannot pump as well.

The mitral valve is located between the left side of the heart’s upper chamber (left atria) and lower chamber (left ventricle), allowing blood to flow from the atria to the ventricle, then closing to prevent it from flowing backward. If the valve is unable to fully open, it decreases blood flow, so the upper heart chamber builds up pressure, which may send blood and fluid seeping into lung tissue, causing pulmonary edema and making breathing difficult. If left untreated, mitral valve stenosis (also known as mitral valve obstruction) can cause serious cardiac conditions.


In adults who have mitral valve stenosis, symptoms develop usually between ages 20 and 50, though some adults may have none. Any activity that raises the heart rate can reveal or exacerbate any symptoms, which may manifest in atrial fibrillation (“AFib”). Other conditions that stress the body and may cause symptoms to appear are pregnancy, a heart or lung infection or other heart problems. The disease may be mild, without observable symptoms, or it may be more severe and gradually become disabling. Its complications may even be life-threatening. If you experience severe symptoms, you may need to go to the hospital for diagnosis and treatment.

Symptoms may include:

  • Waking up due to breathing problems (the most common symptom)
  • Chest discomfort (tightening or squeezing sensation) that increases with activity and occasionally may extend to the arm, neck, jaw or other areas
  • A cough, possibly with bloody phlegm
  • Difficulty breathing during or after exercise, or when lying flat
  • Fatigue
  • Frequent respiratory infections
  • Feeling of pounding heartbeat (palpitations)
  • Swelling of feet or ankles

In children, symptoms may be present from birth but usually become noticeable before the child is two years old. Symptoms include:

  • Cough
  • Poor feeding, or sweating when feeding
  • Poor growth
  • Shortness of breath


Rheumatic fever, an infection related to improperly treated strep throat, is the most frequent cause of mitral valve stenosis in adults. It may take as long as 10 years after the fever for mitral valve problems to develop, and even longer for symptoms to manifest. Since rheumatic fever is no longer common in the United States, mitral stenosis occurs less frequently.

Other contributing factors include:

  • Calcium deposits forming around the mitral valve
  • Radiation treatment to the chest
  • Some medications

Risk factors

Mitral stenosis may be genetic, and children with congenital mitral stenosis may also have other heart defects. Older adults also are at higher risk for mitral valve stenosis, as are those who have had rheumatic fever at any age.


Your doctor should examine you by using a stethoscope to listen to your heart and lungs for any murmur, snapping or other abnormal sound. This exam may also detect arrhythmia or lung congestion, though your blood pressure may be normal. The following diagnostic tests can show narrowing or blockage of the mitral valve and swelling of the atria:

  • Chest X-ray
  • Computed tomography scan (CT or CAT scan) of the heart
  • Echocardiogram
  • Electrocardiogram (ECG or EKG)
  • Magnetic resonance imaging (MRI) of the heart
  • Transesophageal echocardiogram (TEE)


To prevent non-congenital mitral valve stenosis, have any strep infections treated immediately to prevent rheumatic fever, and follow your doctor’s instructions. Tell your physician if you have a family history of congenital heart disease. To prevent complications if you do have mitral stenosis, discuss your heart valve condition with your doctor before receiving any medical treatment. Ask whether you should take preventive antibiotics.