| Proposed role of energy supply in the genesis of delayed afterdepolarizations--implications for ischemic or reperfusion arrhythmias. | |
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MedLine Citation:
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PMID: 2448488 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Delayed afterdepolarizations (DADs) are Ca++-dependent electrophysiological abnormalities, which are evoked by a variety of conditions that induce intracellular Ca++ overload, including fast pacing, isoproterenol, dibutyryl cyclic AMP, and intracellular injection of Ca++. Since Ca++ overload is suspected of playing a role in both ischemic and reperfusion cellular damage, a reasonable hypothesis would be that DADs could play a role in ischemic or reperfusion arrhythmias. No direct proof has, however, been obtained for such a role for DADs. We propose that DADs could be associated with arrhythmias in which there is Ca++ overload of sufficient magnitude to cause an increased oscillatory release of Ca++ from the sarcoplasmic reticulum (SR), provided energy is available in the form of ATP. A sustained increase of Ca++ is likely to reflect energy depletion and therefore exclude a significant contribution of DADs to arrhythmia development. Thus, DADs are more likely to play a role in: (i) reperfusion arrhythmias and (ii) arrhythmias arising in moderately ischemic tissue, than in severe ischemia with marked energy depletion. |
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Authors:
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W A Coetzee; L H Opie; S Saman |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Journal of molecular and cellular cardiology Volume: 19 Suppl 5 ISSN: 0022-2828 ISO Abbreviation: J. Mol. Cell. Cardiol. Publication Date: 1987 Oct |
Date Detail:
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Created Date: 1988-03-15 Completed Date: 1988-03-15 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0262322 Medline TA: J Mol Cell Cardiol Country: ENGLAND |
Other Details:
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Languages: eng Pagination: 13-21 Citation Subset: IM |
Affiliation:
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Department of Medicine, University of Cape Town, Observatory, South Africa. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Arrhythmias, Cardiac / etiology*, metabolism Calcium / metabolism* Coronary Circulation* Coronary Disease / complications* Energy Metabolism Guinea Pigs Heart Conduction System / physiopathology Ion Channels / metabolism* Myocardial Contraction Papillary Muscles / physiology |
| Chemical | |
Reg. No./Substance:
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0/Ion Channels; 7440-70-2/Calcium |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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