| Unidirectional block in a computer model of partially coupled segments of cardiac Purkinje tissue. | |
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MedLine Citation:
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PMID: 8116915 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The initiation of a reentrant circuit requires a zone of slow conduction and a zone of unidirectional block. This study used computer model conditions under which partial coupling between segments of cardiac Purkinje tissue resulted in unidirectional block. The structure used was one-dimensional and divided into three segments: a middle segment of variable length coupled to two long (semi-infinite in concept) segments. The DiFrancesco-Noble equations represented the ionic currents of the membrane. The results show that the possibility of unidirectional block depends on the size of the middle segment and the coupling resistances between the segments. No combination of coupling resistances allowed unidirectional block for middle segments with a length of two space constants (4 mm) or longer. Unidirectional block occurred for many combinations of coupling resistances as the length of the middle segment decreased to around half a space constant (1 mm). The number of length combinations that caused unidirectional block decreased again as segment length further decreased. These results provide a possible mechanism of unidirectional block for situations where islands of viable tissue are connected through nonviable tissue, such as in a healed myocardial infarction. |
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Authors:
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C Cabo; R C Barr |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: Annals of biomedical engineering Volume: 21 ISSN: 0090-6964 ISO Abbreviation: Ann Biomed Eng Publication Date: 1993 Nov-Dec |
Date Detail:
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Created Date: 1994-03-28 Completed Date: 1994-03-28 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 0361512 Medline TA: Ann Biomed Eng Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 633-44 Citation Subset: IM |
Affiliation:
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Department of Biomedical Engineering, Duke University, Durham, NC 27706. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Computer Simulation* Electric Impedance Gap Junctions / physiology Heart Block / physiopathology* Models, Cardiovascular* Purkinje Fibers / physiology* |
| Grant Support | |
ID/Acronym/Agency:
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HL33637/HL/NHLBI NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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