Assertion: heart valve's flap | /r/CapableOf | become stiff
Facets:
value: in this condition
type: OTHER
Source sentences:
text: In this condition, the flaps (cusps) of the aortic valve may become thickened and stiff, or they may fuse together.
text: In this condition, the flaps of the mitral valve become thick or stiff, and they may fuse together.