The pathology of XXXX .

@entity1 @entity712 @entity339 @entity944 @entity3454 @entity397 @entity299 @entity884
The gross criteria for diagnosing prolapsing mitral valve are: 1. interchordal hooding of the involved leaflets, 2. hooding or doming of leaflets towards the left atrium, 3. elongation of the involved leaflets resulting in an increase in valve area, 4. dilatation of the valve annulus in @entity1 with severe @entity339 . The posterior leaflet is most frequently affected. The involved leaflets, in general, are thickened, soft, greyish white and have a smooth atrial surface. Chordae tendineae are described as elongated, tortuous and attenuated or thinned. Deviations from normal chordal insertion have recently been observed which possibly appear to represent the underlying abnormality. Microscopic findings include significant thickening of the spongiosa and the fibrosa, changes in dense collagen fibers in the atrialis layer, occasionally, with fibrin platelet deposits. Histochemical characterization of changes in the spongiosa may also be helpful in the diagnosis. Ultrastructurally, there may be changes in collagen and elastic fibers as well as myxoid areas. On comparison of findings in surgically-removed mitral valves with those of control specimens from autopsy @entity1 with no @entity299 , the length of the anterior and posterior leaflet as well as the annular ring diameter was larger in the valves with prolapse. Two-dimensional echocardiography accurately assessed leaflet length when compared to morphologic measurements, however, the annular diameter during systole or diastole was smaller. In @entity1 with @entity339 requiring surgery, @entity3454 is the most common cause. Annular ring dilatation and chordae tendineae @entity397 appear to contribute substantially to incurrence of the @entity339 . The heart weight is increased in the majority of @entity1 with symptomatic @entity3454 but normal, however, in those without symptoms. The most frequent complication of @entity3454 is @entity339 with or without @entity712 . @entity1 with redundant leaflets may be at high risk of @entity944 . Young @entity1 with abnormal resting ECG, prolonged Q-T interval, family history of @entity944 may also be at a greater risk of @entity944 . The incidence of @entity884 appears higher in those with redundant than in those with nonredundant valves. The incidence of cerebral ischemic events is low.(ABSTRACT TRUNCATED AT 400 WORDS)
