Mitral stenosis

Chest | Cardiology | Mitral stenosis (Disease)


Description

Mitral stenosis (MS) is characterized by obstruction to left ventricular inflow at the level of mitral valve due to structural abnormality of the mitral valve apparatus.

Stenosis of the mitral valve typically occurs decades after the episode of acute rheumatic carditis. Acute insult leads to formation of multiple inflammatory foci (Aschoff bodies, perivascular mononuclear infiltrate) in the endocardium and myocardium. Small vegetations along the border of the valves may also be observed. With time, the valve apparatus becomes thickened, calcified, and contracted, and commissural adhesion occurs, ultimately resulting in stenosis.

Whether the progression of valve damage is due to hemodynamic injury of the already affected valve apparatus or to the chronic inflammatory nature of the rheumatic process is unclear.

Causes and Risk factors

The most common cause of mitral stenosis is rheumatic fever. Other less common etiologies include congenital mitral stenosis, malignant carcinoid disease, systemic lupus erythematosus, rheumatoid arthritis, mucopolysaccharidoses of the Hunter-Hurler phenotype, Fabry disease, Whipple disease, and methysergide therapy. The association of atrial septal defect with rheumatic mitral stenosis is called Lutembacher syndrome.

A number of conditions can simulate the physiology of mitral stenosis: severe nonrheumatic mitral annular calcification, infective endocarditis with large vegetation, left atrial myxoma, ball valve thrombus, or cor triatriatum.

Diagnosis and Treatment

With mitral stenosis (MS), the mitral valve (the valve that lies in between the hearts two left chambers) becomes thickened and immobile, failing to open completely and impeding blood flow. Since MS is fundamentally a mechanical problem, the ultimate solution must be a surgical one - that is, some intervention to relieve the obstruction...