You may feel fine with mitral valve stenosis, or you may have minimal symptoms for decades. However, mild problems can suddenly worsen. See your doctor if you develop:
- Shortness of breath, especially with exertion or when you lie down
- Fatigue, especially during increased physical activity
- Swollen feet or legs
- Heart palpitations — sensations of a rapid, fluttering heartbeat
- Dizziness or fainting
- Heavy coughing, sometimes with blood-tinged sputum
- Chest discomfort or chest pain
- Severe headache, trouble speaking or other symptoms of stroke
Mitral valve stenosis symptoms may appear or worsen anytime your heart rate increases, such as during exercise. An episode of rapid heartbeats may accompany these symptoms. Or they may be triggered by pregnancy or other body stress, such as an infection.
In mitral valve stenosis, pressure that builds up in the heart is then sent back to the lungs, resulting in fluid buildup (congestion) and shortness of breath.
Symptoms of mitral valve stenosis most often appear in between the ages of 30 and 50 in developed nations, but they can occur at any age — even during childhood.
Mitral valve stenosis may also produce signs that your doctor will find during your examination. These may include:
- Heart murmur
- Fluid buildup in the lungs
- Irregular heart rhythms (arrhythmias)
When to see a doctor
Call your doctor for an immediate appointment if you develop fatigue or shortness of breath during physical activity, heart palpitations or chest pain.
If you've been diagnosed with mitral valve stenosis but haven't had symptoms, talk to your doctor about follow-up evaluations.
Causes of mitral valve stenosis include:
- Rheumatic fever. A complication of strep throat, rheumatic fever can damage the mitral valve. Rheumatic fever is the most common cause of mitral valve stenosis. It can damage the mitral valve by causing the flaps to thicken or fuse. Signs and symptoms of mitral valve stenosis might not show up for years.
- Calcium deposits. As you age, calcium deposits can build up around the ring around the mitral valve (annulus), which can occasionally cause mitral valve stenosis.
- Other causes. In rare cases, babies are born with a narrowed mitral valve (congenital defect) that causes problems over time. Surgery is usually recommended to repair congenital mitral stenosis. Other rare causes include radiation to the chest and some autoimmune diseases, such as lupus.
How the heart works
The heart, the center of your circulatory system, consists of four chambers. The two upper chambers (atria) receive blood. The two lower chambers (ventricles) pump blood.
Four heart valves open and close to let blood flow in only one direction through your heart. The mitral valve — which lies between the two chambers on the left side of your heart — comprises two flaps of tissue called leaflets.
The mitral valve opens when blood flows from the left atrium to the left ventricle. Then the flaps close to prevent the blood that has just passed into the left ventricle from flowing backward. A defective heart valve fails to either open or close fully.
Mitral valve stenosis is less common today than it once was because the most common cause, rheumatic fever, is rare in the United States. However, rheumatic fever remains a problem in developing nations.
Risk factors for mitral valve stenosis include:
- History of rheumatic fever
- Untreated strep infections
Like other heart valve problems, mitral valve stenosis can strain your heart and decrease blood flow. Untreated, mitral valve stenosis can lead to complications such as:
- Pulmonary hypertension. This is a condition in which there's increased pressure in the arteries that carry blood from your heart to your lungs (pulmonary arteries), causing your heart to work harder.
- Heart failure. A narrowed mitral valve interferes with blood flow. This can cause pressure to build in your lungs, leading to fluid accumulation. The fluid buildup strains the right side of the heart, leading to right heart failure. With severe narrowing of the mitral valve, over time, the heart's ability to pump blood may be reduced.
- Heart enlargement. The pressure buildup of mitral valve stenosis results in enlargement of your heart's upper left chamber (atrium).
- Atrial fibrillation. The stretching and enlargement of your heart's left atrium may lead to this heart rhythm irregularity in which the upper chambers of your heart beat chaotically and too quickly.
- Blood clots. Untreated atrial fibrillation can cause blood clots to form in the upper left chamber of your heart. Blood clots from your heart can break loose and travel to other parts of your body, causing serious problems, such as a stroke if a clot blocks a blood vessel in your brain.
- Lung congestion (pulmonary edema). Blood and fluid can back up into your lungs, leading to shortness of breath and, sometimes, coughing up of blood-tinged sputum.
The best way to prevent mitral valve stenosis is to prevent its most common cause, rheumatic fever. You can do this by making sure you and your children see your doctor for sore throats. Untreated strep throat infections can develop into rheumatic fever. Fortunately, strep throat is usually easily treated with antibiotics.