Definition

Mitral stenosis is a narrowing of the mitral valve in the heart. This valve is located between the upper chamber and the lower pumping chamber of the left side of the heart. Blood must flow from the atrium, through the mitral valve, and into the ventricle before being pumped out into the rest of the body. Mitral stenosis can result in poor blood flow between the 2 left chambers, which can affect how much blood and oxygen is getting to the body's organs and tissues.

Mitral Valve Stenosis Copyright © Nucleus Medical Media, Inc.

Causes

The most common cause of mitral stenosis is rheumatic fever, which scars the mitral valve. Less commonly, there are some congenital heart defects which may affect the mitral valve and its function. Very rare causes include bacterial endocarditis, blood clots, tumors, or other growths that block blood flow through the mitral valve.

Risk Factors

Mitral stenosis is more common in women and most often appears in adults between the ages of 30 and 50 years old. Other factors that may increase your chance of mitral stenosis include:

• History of rheumatic fever or recurrent strep infections
• Congenital abnormality of the valve
• Family history
• Other chronic conditions, such as high blood pressure, chronic kidney disease, and coronary artery disease (CAD)
• History of radiation treatment to the chest
• IV drug use

Symptoms

Mitral stenosis may cause:

• Difficulty breathing, especially during exercise and when lying flat
• Awakening short of breath in the middle of the night
• Fatigue
• Sensation of rapid or irregular heartbeat
• Cough with exertion
• Coughing up blood
• Swelling of the legs or feet
• Frequent respiratory infections
• Lightheadedness, fainting
• Rarely, chest pain, such as squeezing, pressure, or tightness

Diagnosis

The doctor will ask about your symptoms and medical history. A physical exam will be done. The doctor may be alerted to mitral stenosis by the following:

• Abnormal heart sounds, such as a heart murmur or snap
• Stretching of a vein in the neck
• Signs of fluid in the lungs

Imaging tests evaluate the heart and surrounding structures. These may include:

• Chest x-ray
• Echocardiogram
• Transesophageal echocardiogram
• Cardiac catheterization

Your heart's electrical activity can be monitored with:

• ECG
• Holter monitor—measures activity over a longer period of time, generally 24-48 hours

Treatment

If you have mild mitral stenosis, your condition will need to be monitored, but you may not need immediate treatment for symptoms associated with mitral stenosis. When symptoms become more severe, you may need more aggressive treatment, which may include avoiding exertion and high-salt foods.

Although no longer routinely recommended, you may need to take antibiotics prior to some dental and medical procedures. This is to prevent heart infections. Ask your doctor if you will need to take antibiotics.

Treatment may include:

Prevention

To reduce your chance of mitral stenosis or its complications:

• Get prompt treatment for any infections, especially strep throat.
• Talk to your doctor about prophylactic antibiotic treatment to prevent recurrent strep infections.
• Follow any treatment plans to manage chronic health conditions.
• Avoid excess caffeine and alcohol and avoid all illicit drugs that speed up your heart rate.
• Exercise regularly and monitor your salt intake.