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supravalvar stenosis

[sōō′prə-văl′vər]
n.
  1. Narrowing of the aorta above the aortic valve, usually by a constricting ring.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.