Document Detail


Interaction between spiral and paced waves in cardiac tissue.
MedLine Citation:
PMID:  17384124     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
For prevention of lethal arrhythmias, patients at risk receive implantable cardioverter-defibrillators, which use high-frequency antitachycardia pacing (ATP) to convert tachycardias to a normal rhythm. One of the suggested ATP mechanisms involves paced-induced drift of rotating waves followed by their collision with the boundary of excitable tissue. This study provides direct experimental evidence of this mechanism. In monolayers of neonatal rat cardiomyocytes in which rotating waves of activity were initiated by premature stimuli, we used the Ca(2+)-sensitive indicator fluo 4 to observe propagating wave patterns. The interaction of the spiral tip with a paced wave was then monitored at a high spatial resolution. In the course of the experiments, we observed spiral wave pinning to local heterogeneities within the myocyte layer. High-frequency pacing led, in a majority of cases, to successful termination of spiral activity. Our data show that 1) stable spiral waves in cardiac monolayers tend to be pinned to local heterogeneities or areas of altered conduction, 2) overdrive pacing can shift a rotating wave from its original site, and 3) the wave break, formed as a result of interaction between the spiral tip and a paced wave front, moves by a paced-induced drift mechanism to an area where it may become unstable or collide with a boundary. The data were complemented by numerical simulations, which was used to further analyze experimentally observed behavior.
Authors:
Konstantin Agladze; Matthew W Kay; Valentin Krinsky; Narine Sarvazyan
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2007-03-23
Journal Detail:
Title:  American journal of physiology. Heart and circulatory physiology     Volume:  293     ISSN:  0363-6135     ISO Abbreviation:  Am. J. Physiol. Heart Circ. Physiol.     Publication Date:  2007 Jul 
Date Detail:
Created Date:  2007-07-12     Completed Date:  2007-09-12     Revised Date:  2013-02-04    
Medline Journal Info:
Nlm Unique ID:  100901228     Medline TA:  Am J Physiol Heart Circ Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  H503-13     Citation Subset:  IM    
Affiliation:
Pharmacology and Physiology Department, The George Washington University, 2300 Eye Street, Washington, DC 20037. phynas@gwumc.edu
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MeSH Terms
Descriptor/Qualifier:
Action Potentials / physiology*
Animals
Animals, Newborn
Body Surface Potential Mapping / methods*
Cardiac Pacing, Artificial / methods*
Cells, Cultured
Heart Conduction System / cytology,  physiology*
Models, Cardiovascular*
Myocytes, Cardiac / cytology,  physiology*
Rats
Grant Support
ID/Acronym/Agency:
HL 079722/HL/NHLBI NIH HHS; R01 HL076722/HL/NHLBI NIH HHS; R01 HL076722-01/HL/NHLBI NIH HHS; R01 HL076722-02/HL/NHLBI NIH HHS; R01 HL076722-03/HL/NHLBI NIH HHS
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