Document Detail


Prolonged impairment of coronary vasodilation after reversible ischemia. Evidence for microvascular "stunning".
MedLine Citation:
PMID:  2376075     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Reperfusion after brief, reversible myocardial ischemia is associated with prolonged depression of contractile function (myocardial "stunning"); however, the effect on coronary vascular function has not been defined. Thus, open-chest dogs (n = 14) underwent a 15-minute left anterior descending coronary artery (LAD) occlusion followed by reflow. Four hours after reperfusion, regional myocardial blood flow (microspheres) was significantly (p less than 0.01) lower and coronary vascular resistance significantly (p less than 0.01) higher in the postischemic as compared with the nonischemic endocardium. Furthermore, during maximal vasodilation elicited by intravenous adenosine (n = 6), myocardial blood flow was lower (p less than 0.05) and coronary vascular resistance higher (p less than 0.05) in the postischemic as compared with the nonischemic myocardium, both in the endocardial and in the epicardial layers. Similarly, during maximal dilation elicited by intravenous papaverine (n = 8), myocardial blood flow was lower (p less than 0.05) and vascular resistance higher (p less than 0.05) in the postischemic as compared with the nonischemic endocardium; a directionally similar trend was observed in the epicardium. Four hours after reperfusion, all indexes of reactive hyperemia after a 40-second coronary occlusion were significantly lower in the LAD than in the control circumflex coronary artery (n = 8). There was no appreciable correlation between systolic wall thickening in the stunned myocardium and 1) the resting myocardial perfusion, 2) the hyperemia attained during adenosine or papaverine, and 3) the hyperemic response to a 40-second coronary occlusion. In control dogs that did not undergo a 15-minute LAD occlusion (n = 15), there were no differences in myocardial blood flow or vascular resistance between the LAD-dependent and the circumflex-dependent bed, either before or during adenosine (n = 7) or papaverine (n = 8). Furthermore, reactive hyperemia after a 40-second occlusion did not differ between the LAD and the circumflex artery (n = 8). In conclusion, a brief (15 minute), reversible ischemic insult causes a prolonged increase in resting vascular resistance and a prolonged impairment in vasodilator responsiveness, both of which persist for at least 4 hours. The severity of these vascular derangements is not related to the severity of contractile depression, suggesting that they may represent a relatively independent phenomenon. It is proposed that, in addition to myocardial "stunning," reversible ischemia also causes a microvascular "stunning."
Authors:
R Bolli; J F Triana; M O Jeroudi
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Circulation research     Volume:  67     ISSN:  0009-7330     ISO Abbreviation:  Circ. Res.     Publication Date:  1990 Aug 
Date Detail:
Created Date:  1990-09-06     Completed Date:  1990-09-06     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0047103     Medline TA:  Circ Res     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  332-43     Citation Subset:  IM    
Affiliation:
Department of Medicine, Baylor College of Medicine, Houston, TX 77030.
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MeSH Terms
Descriptor/Qualifier:
Adenosine / pharmacology
Animals
Blood Pressure
Coronary Disease / physiopathology*
Coronary Vessels / drug effects,  physiology,  physiopathology*
Dogs
Heart Rate
Hemodynamics*
Hyperemia / physiopathology
Microcirculation / physiology,  physiopathology
Muscle, Smooth, Vascular / drug effects,  physiology,  physiopathology
Myocardial Reperfusion*
Papaverine / pharmacology
Reference Values
Time Factors
Grant Support
ID/Acronym/Agency:
HL-23161/HL/NHLBI NIH HHS; HL-36277/HL/NHLBI NIH HHS; HL-43151/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
58-61-7/Adenosine; 58-74-2/Papaverine

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