| Prediction of defibrillation outcome by epicardial activation patterns following shocks near the defibrillation threshold. | |
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MedLine Citation:
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PMID: 11021472 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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INTRODUCTION: Ventricular defibrillation is probabilistic and shock strength dependent. We investigated the relationship between defibrillation outcome and postshock activation patterns for shocks of the same strength (approximately 50% probability of success for defibrillation [ED50] to yield an equal number of successful and failed shocks). METHODS AND RESULTS: In five pigs, 10 shocks of approximately ED50 strength (right ventricle-superior vena cava, biphasic, 6/4 msec) were delivered after 10 seconds of ventricular fibrillation (VF). Epicardial activation sequences following shocks were mapped with a 504-electrode shock and analyzed by animating dV/dt of the electrograms. Intercycle interval (ICI, time between the onset of successive postshock cycles), wavefront conduction time (WCT, time between the earliest and latest activation of a cycle), and overlapping index (WCT of cycle[n]/ICI of cycle[n+1]) were determined for the first five postshock cycles. An overlapping index >1 indicates overlap between successive cycles. Of 50 defibrillation attempts, 25 were successes. There was no difference between successful and failed episodes for both ICI (68 +/- 9 msec vs 62 +/- 10 msec) and WCT (97 +/- 24 msec vs 100 +/- 14 msec) of cycle 1. However, starting at cycle 2, the ICI was longer, and the WCT was shorter for successful than failed episodes (P < 0.01). Overlapping cycles (index > 1) were found during the transition from cycles 2 through 5 in all failed (index >1) and in no successful episodes. CONCLUSIONS: (1) Defibrillation outcome cannot be determined during the first postshock cycle. (2) At least three rapid successive cycles with overlap of cycles 2 and 3 are present in all failed and in no successful episodes. (3) The overlapping index is a marker to predict defibrillation outcome. |
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Authors:
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N Chattipakorn; P C Fotuhi; R E Ideker |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: Journal of cardiovascular electrophysiology Volume: 11 ISSN: 1045-3873 ISO Abbreviation: J. Cardiovasc. Electrophysiol. Publication Date: 2000 Sep |
Date Detail:
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Created Date: 2001-02-05 Completed Date: 2001-02-08 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 9010756 Medline TA: J Cardiovasc Electrophysiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 1014-21 Citation Subset: IM |
Affiliation:
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Department of Medicine, University of Alabama at Birmingham, USA. toon@crml.uab.edu |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Body Surface Potential Mapping Electric Countershock* / methods Female Male Pericardium / physiology Swine Treatment Outcome |
| Grant Support | |
ID/Acronym/Agency:
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HL-33637/HL/NHLBI NIH HHS; HL-42760/HL/NHLBI NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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