Mitral valve replacement is a procedure whereby the diseased mitral valve of a patient's heart is replaced by either a mechanical or tissue (bioprosthetic) valve.
The mitral valve may need to be replaced because:
The valve is leaky (mitral valve regurgitation)
The valve is narrowed and doesn't open properly (mitral valve stenosis)Causes of mitral valve disease include infection, calcification and inherited collagen disease. [Source: Wikipedia 
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