Mitral stenosis Health Article

Definition

Mitral stenosis is a heart valve disorder that involves the mitral valve. This valve separates the upper and lower chambers on the left side of the heart. Stenosis refers to a condition in which the valve does not open fully, restricting blood flow.

Alternative Names

Mitral valve obstruction

Causes, incidence, and risk factors

Mitral stenosis prevents the valve from opening properly. This prevents proper blood flow between the left atrium (upper chamber of the heart) and left ventricle (lower chamber of the heart). As the valve area becomes smaller, less blood flows to the body. The upper heart chamber swells as pressure builds up. Blood may flow back into the lungs. Fluid then collects in the lung tissue ( pulmonary edema), making it hard to breathe. See also: heart failure.

In adults, mitral stenosis occurs most often in those who've had rheumatic fever (a condition that may develop after strep throat or scarlet fever). The valve problems develop 5 - 10 years after the rheumatic fever. Rheumatic fever is becoming rare in the United States, so mitral stenosis is also less common.

Only rarely do other factors cause mitral stenosis in adults. These include calcium deposits forming around the mitral valve, radiation treatment to the chest, and some medications.

Children may be born with mitral stenosis (congenital) or other birth defects involving the heart that cause mitral stenosis. Often, there are other heart defects present, along with the mitral stenosis.

Mitral stenosis may run in families.

Symptoms

In adults there may be no symptoms at all. Symptoms may, however, appear or get worse with exercise or any activity that raises the heart rate. In adults, symptoms usually develop between the ages of 20 and 50.

Symptoms may begin with an episode of atrial fibrillation or may be triggered by pregnancy or other stress on the body such as infection in the heart or lungs, or other heart disorders.

Symptoms may include:

• Chest discomfort (rare)
  • Increases with activity, decreases with rest
  • Radiates to the arm, neck, jaw, or other areas
  • Tight, crushing, pressure, squeezing, constricting
• Cough, possibly bloody (hemoptysis)
• Difficulty breathing during or after exercise or when lying flat; may wake up with difficulty breathing
• Fatigue, becoming tired easily
• Frequent respiratory infections such as bronchitis
• Sensation of feeling the heart beat (palpitations)
• Swelling of feet or ankles

In infants and children, symptoms may be present from birth (congenital), and almost always develop within the first 2 years of life. Symptoms include:

• Bluish discoloration of the skin or mucous membranes (cyanosis)
• Poor growth
• Shortness of breath