Mitral valve prolapse Causes
Primary mitral valve prolapse syndrome is a congenital connective tissue disease, its exact cause has not known. Can occur in all age groups, a higher incidence in women, in 14-30 year-old female. 1/3 of patients with no other organic heart disease, but only for the clinical manifestations of mitral valve prolapse, can also be seen in patients with Marfan syndrome, systemic lupus erythematosus, polyarteritis nodosa, often the back leaves prolapse. In some patients with genetic abnormalities of collagen, the performance of electron microscopy for the generation of type Ⅲ collagen fibers and fracture reduction, connective tissue Center degeneration of collagen fibers, cellulose deposition; elastic fibers from the off and dissolved .
Mitral valve prolapse is characterized by myxoid mitral valve degeneration, sponge layer hyperplasia and invasive fiber layer, sponge layer with marked thickening of proteoglycan accumulation, face the limitations of atrial valve thickening, and platelet surface of cellulose deposition. Prolapse of the mitral valve chordae tendineae bulging between the part toward the left atrium of the heart valve leaflets were hemispherical bulging uplift, longer valve area increased, the expansion of severe cases of mitral annulus. At the same time, chordal thinning, variable length, distortion, followed by fibrosis and thickening. Abnormal chordae valve involvement in the most significant Department, due to abnormal chordae tendineae, mitral valve uneven stress, cause exfoliative valve mucous degeneration organizations; increased chordae tendineae tension can occur fracture. Papillary muscles and surrounding myocardium may be due to excessive traction, friction and cause ischemia and fibrosis. Mitral valve calcification will increase prolapse.
Some mitral valve prolapse may be secondary by rheumatoid inflammation or infection, more see the front leaflet prolapse. In addition, mitral valve prolapse can also be caused by coronary heart disease, cardiomyopathy, congenital heart disease. Hyperthyroidism in patients is usually combined with mitral valve prolapse.