Mitral valvular is the most commonly involved site of heart disease, usually is mitral stenosis and mitral insufficiency. Chronic rheumatic heart valve disease is the most common cause of mitral stenosis. Other cause of mitral stenosis are congenital mitral ring calcification or mitral valve dysplasia. In 2 / 3 Patients with mitral stenosis is women. About 40% of rheumatic heart disease (RHD) in patients is simple mitral stenosis.
Mitral stenosis is formation of the inflammatory edema in valve at the junction and bottom. As a result of fibrosis and calcinosis, extensive valve thickening, adhesion, fusion tendons shorten, rigid valve, leading to Mitral valve deformation and stenosis, significant stenosis as a hole cracks. According to the degree, Mitral stenosis can divided into diaphragm and funnel-shaped. Main valve body in diaphragm-type mitral stenosis have no lesions or less lesions; funnel-type mitral stenosis have valve obvious thickening and fibrosis, chordae tendineae and papillary muscles and reduce the adhesion significantly, the whole hardened valve was funnel-shaped, limited activity. Often accompanied by varying degrees of incompetence. Valve calcification further narrow leaves, and caused by thrombosis and embolism. Congenital mitral stenosis, the thickening of valve leaflets, fusion junction, thickened or shortened chordae tendineae, papillary muscle hypertrophy or fibrosis, can have a narrow valve ring, valve may have a fiber band. The most characteristic is that have only one papillary muscle and parachute-like deformity of the mitral valve, the two tendons of the valve are connected to the papillary muscles, the entire mitral valve seem like the opened parachute.