Mitral stenosis

Rheumatic fever is the most common cause of mitral stenosis clinically. It is a heart disease mainly involving valvular lesions that remains after carditis caused by acute rheumatic fever, and is chronic rheumatic heart disease. Among these, involvement of the mitral valve accounts for 95%–98%, of which isolated mitral valve lesions account for 70%–80%, and mitral valve combined with aortic valve lesions account for 20%–30%; it is often combined with mitral or aortic valve lesions. In recent years, due to strengthened prevention and treatment of rheumatic fever, the incidence of rheumatic valvular heart disease has significantly decreased. Mitral stenosis is the most common type of rheumatic valvular heart disease, with 40% of patients having isolated mitral stenosis. Due to recurrent rheumatic fever, in the early stage the mitral valve mainly shows edema, inflammation, and vegetation (exudate) formation at the commissures and their bases. In the later stage, during the healing process, due to fibrin deposition and fibrous changes, adhesions and fusion gradually form at the commissures of the anterior and posterior leaflets, with thickening, roughening, sclerosis, calcification of the leaflets, as well as shortening and mutual adhesion of the chordae tendineae, restricting valvular mobility and opening, resulting in valvular orifice stenosis. Rare other causes include senile mitral annular or subannular calcification, congenital stenosis, and connective tissue diseases.