Document Detail


Micropatterns of propagation.
MedLine Citation:
PMID:  16646586     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Alterations in microscopic conduction could contribute to microreentry and arrhythmogenesis in pathological settings. This chapter reviews microconduction in the ventricular myocardium. Gap junctions play a significant role in longitudinal and transverse propagation of the action potential wavefront in the ventricle. Studies of microscopic conduction in patterned cultures of neonatal rodent myocytes have provided novel insights into the role of gap junctions, the effects of uncoupling versus altered excitability, and the contribution of discontinuities and branching. Decreased gap junctional coupling can contribute to slowing of conduction and development of unidirectional block. However, in the setting of structural inhomogeneities and unbalanced current source and load, decreased coupling can, at times, improve conduction and be 'anti-arrhythmic,' attesting to the complexity of intercellular coupling as a therapeutic target. Genetically engineered mouse models of Cx43 depletion demonstrate slow conduction and arrhythmogenesis that appears to be reentrant in nature. Studies in these models provide novel insights into the contribution of gap junctions to impulse propagation and arrhythmogenesis in the intact heart. Overall, gap junction expression, distribution and heterogeneity are important contributors to microscopic conduction, and alterations in any of these can contribute to the development of an arrhythmogenic substrate in pathological states.
Authors:
Peter J Lee; Steven M Pogwizd
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Publication Detail:
Type:  Journal Article; Review    
Journal Detail:
Title:  Advances in cardiology     Volume:  42     ISSN:  0065-2326     ISO Abbreviation:  Adv Cardiol     Publication Date:  2006  
Date Detail:
Created Date:  2006-05-01     Completed Date:  2006-07-06     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0270063     Medline TA:  Adv Cardiol     Country:  Switzerland    
Other Details:
Languages:  eng     Pagination:  86-106     Citation Subset:  IM    
Affiliation:
University of Illinois at Chicago, 60612-7323, USA.
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MeSH Terms
Descriptor/Qualifier:
Action Potentials / physiology
Animals
Arrhythmias, Cardiac / physiopathology
Cells, Cultured
Connexins / genetics,  physiology
Fatty Acids, Monounsaturated / pharmacology
Gap Junctions / metabolism,  physiology*
Gene Deletion
Heart / physiology*
Humans
Mice
Mice, Knockout
Tetrodotoxin / pharmacology
Chemical
Reg. No./Substance:
0/Connexins; 0/Fatty Acids, Monounsaturated; 2091-29-4/palmitoleic acid; 4368-28-9/Tetrodotoxin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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