Mitral stenosis

Injury	Disease	Nutrition	Poison

Symptoms	Surgery	Test	Special Topic

Heart, section through the middle

Heart, front view

Mitral stenosis

Heart valves

Heart valve surgery - series

Mitral stenosis

Definition:

Mitral stenosis is a narrowing or obstruction of the opening of the mitral valve, which separates the upper and lower chambers on the left side of the heart. This prevents adequate blood flow between the left atrium (upper chamber) and ventricle (lower chamber).

Alternative Names:
Mitral valve obstruction
Causes, incidence, and risk factors:

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Mitral stenosis is a heart valve disorder. Symptoms usually develop between the ages of 20 and 50. It most commonly occurs in people who have had rheumatic fever. Since rheumatic fever rates are declining in the United States, the incidence of mitral stenosis is also decreasing. Only rarely do other disorders cause mitral stenosis.

The condition may be present from birth (congenital), but it seldom occurs as a single defect. Congenital mitral stenosis is more often part of a complex heart deformity.

Mitral stenosis prevents the valve from opening properly and obstructs the blood flow from the left atrium to the left ventricle. This narrowing can reduce the amount of blood that flows forward to the body. The atrium enlarges as pressure builds up and blood may flow back into the lungs, resulting in pulmonary edema (fluid in the lung tissue).

The main risk factor for mitral stenosis is a history of rheumatic fever. 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, lungs, etc.) or other cardiac disorders.

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