| Impact of myocardial ischemia and reperfusion on ventricular defibrillation patterns, energy requirements, and detection of recovery. | |
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MedLine Citation:
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PMID: 12034662 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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BACKGROUND: Shocks that have defibrillated spontaneous ventricular fibrillation (VF) during acute ischemia or reperfusion may seem to have failed if VF recurs before the ECG amplifier recovers after shock. This could explain why the defibrillation threshold (DFT) for spontaneous VF appears markedly higher than for electrically induced VF. METHODS AND RESULTS: The DFT for electrically induced VF (E-DFT) was determined in 15 pigs before ischemia, followed by left anterior ascending or left circumflex artery occlusion. VF was electrically induced 20 minutes after occlusion, followed 5 minutes later by reperfusion. Whether spontaneous or electrically induced, VF during occlusion or reperfusion was treated with up to 3 shocks at 1.5xE-DFT. If all 3 shocks failed, shock strength was increased. Thirty minutes after reperfusion, the other artery was occluded and the protocol was repeated. Defibrillation was considered successful if postshock sinus/idioventricular rhythm was present for > or = 30 seconds. VF recurring within 30 seconds after the shock was considered immediate or delayed if the first postshock activation complex in a rapidly restored ECG recording was VF or sinus/idioventricular rhythm, respectively. Defibrillation efficacy at 1.5xE-DFT was significantly higher for electrically induced ischemic VF (76%) than for spontaneous VF (31%). The incidence of delayed recurrence after electrically induced nonischemic (3%) or ischemic (20%) VF was significantly lower than after spontaneous VF (75%). Mean VF recurrence time after spontaneous VF was 4.6+/-5.3 seconds. CONCLUSIONS: Spontaneous VF can be halted by a shock but then quickly restart before a standard ECG amplifier has recovered from postshock saturation, making it appear that the shock failed. |
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Authors:
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Hao Qin; Gregory P Walcott; Cheryl R Killingsworth; Dennis L Rollins; William M Smith; Raymond 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: Circulation Volume: 105 ISSN: 1524-4539 ISO Abbreviation: Circulation Publication Date: 2002 May |
Date Detail:
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Created Date: 2002-05-29 Completed Date: 2002-06-07 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 0147763 Medline TA: Circulation Country: United States |
Other Details:
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Languages: eng Pagination: 2537-42 Citation Subset: AIM; IM |
Affiliation:
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Department of Physiology and Biophysics, Medicine, University of Alabama at Birmingham, 35294-0019, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Disease Models, Animal Electric Countershock / methods* Electrocardiography Electrophysiologic Techniques, Cardiac / methods Female Heart Conduction System / physiopathology* Male Myocardial Ischemia / complications, physiopathology* Myocardial Reperfusion* Recurrence Swine Time Factors Treatment Outcome Ventricular Fibrillation / complications, physiopathology* |
| Grant Support | |
ID/Acronym/Agency:
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HL-28429/HL/NHLBI NIH HHS; HL-42760/HL/NHLBI NIH HHS; HL-63775/HL/NHLBI NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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