mitral stenosis

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A narrowing of the mitral valve, usually caused by disease and resulting in an obstruction to the flow of blood from the left atrium to the left ventricle.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun obstruction or narrowing of the mitral valve (as by scarring from rheumatic fever)