Mitral stenosis
| Mitral stenosis | |
|---|---|
 |
|
| Mitral stenosis with marked thickening of the leaflets and left atrial hypertrophy. Superior view. Autopsy preparation. | |
| Classification and external resources | |
| Specialty | Cardiology |
| ICD-10 | I05.0, I34.2, Q23.2 |
| ICD-9-CM | 394.0, 396.0, 746.5 |
| DiseasesDB | 8288 |
| MedlinePlus | 000175 |
| eMedicine | emerg/315 ped/2517 |
| MeSH | D008946 |
Mitral stenosis is a valvular heart disease characterized by the narrowing of the orifice of the mitral valve of the heart.
Signs and symptoms of mitral stenosis include the following:
Fatigue and weakness increase with exercise and pregnancy.
The natural history of mitral stenosis secondary to rheumatic fever (the most common cause) is an asymptomatic latent phase following the initial episode of rheumatic fever. This latent period lasts an average of 16.3 ± 5.2 years. Once symptoms of mitral stenosis begin to develop, progression to severe disability takes 9.2 ± 4.3 years.
In individuals having been offered mitral valve surgery but refused, survival with medical therapy alone was 44 ± 6% at 5 years, and 32 ± 8% at 10 years after they were offered correction.
Almost all cases of mitral stenosis are due to disease in the heart secondary to rheumatic fever and the consequent rheumatic heart disease. Uncommon causes of mitral stenosis are calcification of the mitral valve leaflets, and as a form of congenital heart disease. However, there are primary causes of mitral stenosis that emanate from a cleft mitral valve. It is the most common valvular heart disease in pregnancy.
Other causes include infective endocarditis where the vegetations may favor increase risk of stenosis. Other rare causes include mitral annular calcification, endomyocardial fibroelastosis, malignant carcinoid syndrome, systemic lupus erythematosus, whipple disease, fabry disease, and rheumatoid arthritis. hurler' disease, hunter's disease, amyloidosis.
The normal area of the mitral valve orifice is about 4 to 6 cm2. In normal cardiac physiology, the mitral valve opens during left ventricular diastole, to allow blood to flow from the left atrium to the left ventricle. A normal mitral valve will not impede the flow of blood from the left atrium to the left ventricle during (ventricular) diastole, and the pressures in the left atrium and the left ventricle during ventricular diastole will be equal. The result is that the left ventricle gets filled with blood during early ventricular diastole, with only a small portion of extra blood contributed by contraction of the left atrium (the "atrial kick") during late ventricular diastole.
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