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.