cardiopulmonary murmur

n.
  1. A murmur, synchronous with the heart's beat but disappearing when the breath is held, due to movement of the air in a segment of lung compressed by the contracting heart.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.