Document Detail


Redistribution of myocardial blood flow distal to a dynamic coronary arterial stenosis by sympathomimetic amines: comparison of dopamine, dobutamine and isoproterenol.
MedLine Citation:
PMID:  7270436     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The effects of dopamine, dobutamine and isoproterenol on coronary hemodynamics, severity of stenosis, distal bed resistance and transmural myocardial perfusion gradients with radioactive microspheres were studied in dogs with a mild obstruction of the left circumflex coronary artery anesthetized with morphine-chloralose. Changes in transmural blood flow were related to the ratio of the diastolic aortic pressure-time index to tension-time index (DPTI/TTI) and the ratio of the distal diastolic coronary pressure-time index to tension-time index (DDPTI/TTI). At doses of 5 microgram/kg per min, dopamine had no significant effect on DPTI/TTI, DDPTI/TTI or endocardial/epicardial flow ratio; however, dobutamine produced a slight decrease in this flow ratio and in DDPTI/TTI. At doses of 10 microgram/kg per min, both drugs produced a significant (p less than 0.05) reduction in diastolic coronary pressure distal to the stenosis. DDPTI/TTI and endocardial/epicardial flow ratio without change in DPTI/TTI. In comparison, isoproterenol (0.01 and 0.05 microgram/kg per min) produced dose-related decreases in endocardial/epicardial flow ratio, DDPTI/TTI and DPTI/TTI. During infusion of each sympathomimetic agent, there was a corresponding reduction in distal bed vascular resistance but a concomitant increase in stenosis resistance. The results also show that dopamine and dobutamine, as well as isoproterenol, area capable of producing a maldistribution of coronary blood flow distal to a mild coronary arterial stenosis and that such a redistribution of glow is dependent on dose, reduction of the distal diastolic coronary pressure-time index and decrease in DDPTI/TTI. It is further concluded that hemodynamic changes distal to a coronary arterial stenosis seriously jeopardize the usefulness of DPTI/TTI; however, DDPTI/TTI can be used to predict drug effects on the endocardial/epicardial flow ratio in an ischemic area. This study demonstrates that "fixed" stenoses can undergo dynamic processes and sympathomimetic amines increase the resistance to flow through a stenotic coronary artery in the nonfailing heart.
Authors:
D C Warltier; M Zyvoloski; G J Gross; H F Hardman; H L Brooks
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of cardiology     Volume:  48     ISSN:  0002-9149     ISO Abbreviation:  Am. J. Cardiol.     Publication Date:  1981 Aug 
Date Detail:
Created Date:  1981-10-25     Completed Date:  1981-10-25     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0207277     Medline TA:  Am J Cardiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  269-79     Citation Subset:  AIM; IM    
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MeSH Terms
Descriptor/Qualifier:
Animals
Catecholamines / pharmacology*
Coronary Circulation / drug effects*
Coronary Disease / physiopathology*
Coronary Vessels / physiopathology
Diastole / drug effects
Dobutamine / pharmacology*
Dogs
Dopamine / pharmacology*
Hemodynamics / drug effects
Isoproterenol / pharmacology*
Models, Biological
Time Factors
Vascular Resistance / drug effects
Grant Support
ID/Acronym/Agency:
HL 25120/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Catecholamines; 34368-04-2/Dobutamine; 7683-59-2/Isoproterenol

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


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