| Contribution of asynchrony and nonuniformity to mechanical interaction in normal and stunned myocardium. | |
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MedLine Citation:
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PMID: 9374747 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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In anesthetized pigs, we investigated whether asynchrony (delta T) and nonuniformity (regional differences) in contractility (delta E) could describe the interaction between normal and stunned myocardium. Mechanical interaction was evaluated by regional postsystolic work (PSW) before and after production of stunning by a 5-min occlusion of the left circumflex coronary artery [LCX (LCX stunning)] and a subsequent 10-min occlusion of the left anterior descending coronary artery [LAD (LAD stunning)]. delta T and delta E were intensified by intracoronary (LAD) infusions of dobutamine. From regional end-systolic pressure-segment length relationships, systolic segment shortening (SS), end-systolic elastance (E), external work (EW), and PSW were determined. LCX stunning decreased SSLCX from 14 +/- 2 (mean +/- SE, n = 9) to 10 +/- 2% and ELCX from 103 +/- 25 to 52 +/- 7 mmHg/mm, whereas the LAD region was unaffected. EWLCX decreased from 165 +/- 16 to 138 +/- 20 mmHg.mm, whereas PSWLCX increased from -4 +/- 6 to 8 +/- 3 mmHg.mm. Additional LAD stunning reduced SSLAD from 16 +/- 2 to 9 +/- 3% and ELAD from 79 +/- 10 to 31 +/- 6 mmHg/mm, without affecting SSLCX and ELCX. In the normal myocardium, PSWLAD increased and PSWLCX decreased, but, during local LAD dobutamine infusions after stunning, both PSWLCX and PSWLAD increased. In normal myocardium, the changes in PSWLCX could be described by delta T (65 +/- 11%) and delta E (37 +/- 15%). After stunning of the LAD area, the contribution of delta E increased to 55 +/- 14% at the expense of delta T (37 +/- 15%). Similar contributions of delta E (54 +/- 13%) and delta T (57 +/- 13%) were found when both the LCX and LAD distribution areas were stunned. In normal myocardium, both delta T and delta E modulate mechanical interaction, with the contribution of delta T exceeding that of delta E. In stunned myocardium, both factors contribute, but the contribution shifts in favor of delta E. |
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Authors:
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D Fan; L K Soei; R Stubenitsky; E Boersma; D J Duncker; P D Verdouw; R Krams |
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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: The American journal of physiology Volume: 273 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1997 Nov |
Date Detail:
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Created Date: 1997-12-16 Completed Date: 1997-12-16 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0370511 Medline TA: Am J Physiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: H2146-54 Citation Subset: IM |
Affiliation:
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Department of Cardiology, Erasmus University Rotterdam, The Netherlands. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Coronary Vessels / physiology Diastole Dobutamine / pharmacology Elasticity Female Heart / drug effects, physiology*, physiopathology* Heart Rate Hemodynamics* / drug effects Male Models, Cardiovascular Myocardial Contraction* / drug effects Myocardial Stunning / physiopathology* Reference Values Swine Systole Ventricular Function, Left |
| Chemical | |
Reg. No./Substance:
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34368-04-2/Dobutamine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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