heart blockn. A condition in which faulty transmission of the impulses that control the heartbeat results in a lack of coordination in the contraction of the atria and ventricles of the heart.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.heart block n (Pathology) impaired conduction or blocking of the impulse that regulates the heartbeat, resulting in a lack of coordination between the beating of the atria and the ventricles. Also called: Adams-Stokes syndrome or atrioventricular block Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014heart? block` n. a defect in the electrical impulses of the heart resulting in any of various arrhythmias or irregularities in the heartbeat. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.heart blockA condition in which the electrical impulses in the heart are blocked at points in the conduction system.Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited