Document Detail


High afterload during 10 min of regional ischaemia affects diastolic creep but not systolic function in reperfused (stunned) myocardium.
MedLine Citation:
PMID:  8876746     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The effect of afterload during regional ischaemia on myocardial stunning was studied in 15 pentobarbital anaesthetized cats. 10 min occlusion of the left anterior descending artery (LAD) was followed by 60 min of reperfusion. Afterload was decreased by intravenous infusion of nitroglycerine 3-8 micrograms kg-1 min-1 in group I (n = 8); left ventricular peak systolic pressure (LVSP) 84 +/- 4 mmHg (mean +/- SEM) during coronary artery occlusion. In group II (n = 7) LVSP was increased to 188 +/- 10 mmHg by inflating an intraaortic balloon during coronary artery occlusion. Regional function in the LAD perfused region was evaluated by cross-oriented sonomicrometry. Myocardial tissue blood flow was evaluated by radio-labelled microspheres. Afterload alterations did not affect regional systolic shortening (10.8 +/- 2.0% vs. 11.0 +/- 1.5% in group I and II, respectively, after 60 min of reperfusion). However, increased end-diastolic dimensions (diastolic creep) in both the circumferential and longitudinal segments were markedly more pronounced in the high afterload group (group II). Also important, the markedly increased myocardial tissue blood flow during reperfusion in group II as compared with group I (2.30 +/- 0.18 vs. 1.34 +/- 0.08 mL min-1 g-1 and 2.58 +/- 0.23 vs. 1.49 +/- 0.07 mL min-1 g-1 in subepicardial and subendocardial layers in the LAD perfused region) suggests that increased diastolic creep increased metabolic demands. This study indicates that passive stretching of the ischaemic area during coronary artery occlusion is an important mechanism behind diastolic creep.
Authors:
S E Rynning; H Brunvand; S Birkeland; E Hexeberg; K Grong
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Acta physiologica Scandinavica     Volume:  158     ISSN:  0001-6772     ISO Abbreviation:  Acta Physiol. Scand.     Publication Date:  1996 Sep 
Date Detail:
Created Date:  1997-01-23     Completed Date:  1997-01-23     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370362     Medline TA:  Acta Physiol Scand     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  39-44     Citation Subset:  IM    
Affiliation:
Surgical Research Laboratory, Haukeland University Hospital, Bergen, Norway.
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MeSH Terms
Descriptor/Qualifier:
Animals
Aorta, Thoracic / physiology
Cardiac Output / physiology
Cats
Coronary Circulation / physiology
Diastole / physiology*
Male
Microspheres
Myocardial Ischemia / physiopathology*
Myocardial Reperfusion Injury / physiopathology*
Systole / physiology*
Vasodilation / physiology

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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