Mitral valve replacement is a surgical procedure in which the diseased mitral valve of the heart is replaced by a mechanical or biological tissue valve.
The mitral valve can become diseased, preventing it from adequately controlling the direction of the flow of blood between the left atrium and left ventricle. It also can become insufficient (regurgitant) and allow blood to flow backwards into the left atrium from the left ventricle during ventricular contraction (systole). In addition, the mitral valve can become stenotic (narrowed), preventing the flow of blood from the left atrium into the left ventricle during ventricular filling (diastole). In mitral valve prolapse, one or more of the mitral valve's cusps protrude back into the left atrium during ventricular contraction. Mitral valve replacement is performed to remove the diseased valve and provide a new mechanical valve or biological tissue valve that correctly controls the direction of blood flow.
Approximately 65,000 valve repairs and replacements are performed in the United States each year.
Twice as many women as men are affected by mitral valve stenosis. About 60% of patients with mitral valve stenosis have had rheumatic fever. After rheumatic fever there is usually a latency period of 10–20 years before symptoms of mitral valve stenosis appear. The prevalence of mitral valve stenosis has declined in the United States because there has been a decline in the number of cases of rheumatic fever. Mitral valve stenosis may be present at birth (congenital); however, it rarely occurs alone but rather in conjunction with other heart defects.
Mitral valve prolapse is the most common condition of the heart valves, and is present in about 2% of the general population. Recent studies indicate that similar numbers of men and women have mitral valve prolapse. Having this condition does not guarantee that mitral insufficiency will develop. Patients with a history of rheumatic fever, coronary artery disease, infective endocarditis, or collagen vascular disease also may develop mitral insufficiency.
|
|
Author Info: Allison Joan Spiwak MSBME, The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Surgery, 2004 |