precordial lead

[lēd]
n.
  1. A lead of an electrocardiograph that has one electrode placed in any of six standard positions on the chest and another electrode placed on a limb.
  2. A record obtained from such a lead.chest lead
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.