Document Detail

Effect of myocardial contraction on systolic coronary resistance in conscious dogs.
MedLine Citation:
PMID:  3308714     Owner:  NLM     Status:  MEDLINE    
We studied the effect of cardiac contraction on systolic coronary resistance under the conditions of maximally dilated coronary resistance vessels in six conscious dogs. Subendocardial segment length in areas supplied by the left circumflex coronary artery, left ventricular pressure and left circumflex coronary artery flow were simultaneously measured. At 5 sec after release of the first 2 min of left circumflex coronary artery occlusion, diastolic coronary blood flow revealed its peak value in association with markedly depressed regional contractile function. With collateral development induced by repeated 2 min left circumflex coronary artery occlusions, segmental dysfunction during occlusion and early reperfusion was progressively attenuated. Before and after collateral development, diastolic coronary resistance at 5 sec of reperfusion remained unchanged, but systolic coronary resistance increased by 41% secondary to restoration of regional myocardial shortening. In each animal, normalized regional shortening correlated well with changes in systolic coronary resistance. The fraction of systolic coronary resistance due to active regional myocardial contraction was 52%. These studies demonstrate that when coronary vasomotor tone is abolished, regional myocardial contraction impedes the coronary systolic flow in proportion to the extent of shortening.
M Fujita; D P McKown; M D McKown; D Franklin
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  International journal of cardiology     Volume:  16     ISSN:  0167-5273     ISO Abbreviation:  Int. J. Cardiol.     Publication Date:  1987 Sep 
Date Detail:
Created Date:  1987-11-19     Completed Date:  1987-11-19     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  8200291     Medline TA:  Int J Cardiol     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  235-47     Citation Subset:  IM    
Dalton Research Center, University of Missouri-Columbia 65211.
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MeSH Terms
Blood Flow Velocity
Collateral Circulation
Coronary Circulation
Coronary Vessels / physiology*
Myocardial Contraction*
Time Factors
Vascular Resistance*
Grant Support

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

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