[Mechanism of XXXX and @entity3585 in hypertrophic obstructive cardiomyopathy].

@entity1 @entity3585 @entity299 @entity14087
Two-dimensional echocardiographic studies were performed for 22 @entity1 with @entity14087 and @entity299 ( @entity299 ) of the mitral valve to clarify the mechanism of @entity299 and @entity3585 . The long-axis view of the left ventricle showed that a distal portion of the anterior mitral leaflet became surplus when the mitral valve was closed in 15 of 16 @entity1 with @entity299 -septal contact and in four of six @entity1 without it. In these @entity1 , the mitral leaflet coaptation was displaced anteriorly, and/or the anterior leaflet was elongated, showing an anterior motion. In an unusual @entity1 with @entity299 -septal contact, a distal portion of the long posterior mitral leaflet was surplus. The remaining two @entity1 without @entity299 -septal contact had a rather widely coapted portion of the mitral leaflets. The distal surplus portion and the coapted portion of the mitral valve were displaced anteriorly prior to the onset of ejection, and moved forward and protruded into the outflow tract more rapidly and more excessively than the papillary muscles during early to mid systole in all @entity1 . Then, the distal mitral valve and the chordae tendineae adopted the configuration of an inverted V in mid systole. The tip of the surplus leaflet contacted the interventricular septum in @entity1 with @entity299 -septal contacts. In the short-axis view of the left ventricle, the central portion of the distal mitral valve moved forward excessively and bent like an inverted U during early to mid systole. Therefore, @entity299 of the distal mitral valve is thought to be caused by the hydrodynamic force generated by the ejection flow. This force is supposed to be not only due to the Venturi effect, but is more properly understood as a "pushing force". @entity3585 is considered to be formed by the protruding distal mitral valve and the hypertrophied septum.
