breath-holding test

n.
  1. A test used as a rough index of cardiopulmonary reserve, measured by the length of time a person can hold his or her breath. Diminished cardiac or pulmonary reserve is indicated if one's breath is held for less than 20 seconds.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.