| Contribution of extravascular compression to reduction of maximal coronary blood flow. | |
| | |
MedLine Citation:
|
PMID: 1733324 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Effects of ventricular compression on maximally dilated left circumflex coronary blood flow were investigated in seven mongrel dogs under pentobarbital anesthesia. The left circumflex artery was perfused with the animals' own blood at a constant pressure (63 mmHg) while left ventricular pressure was experimentally altered. Adenosine was infused to produce maximal vasodilation, verified by the hyperemic response to coronary occlusion. Alterations of peak left ventricular pressure from 50 to 250 mmHg resulted in a linear decrease in total circumflex flow of 1.10 ml.min-1 x 100 g heart wt-1 for each 10 mmHg of peak ventricular to coronary perfusion pressure gradient; a 2.6% decrease from control levels. Similar slopes were obtained for systolic and diastolic flows as for total mean flow, implying equal compressive forces in systole as in diastole. Increases in left ventricular end-diastolic pressure accounted for 29% of the flow changes associated with an increase in peak ventricular pressure. Doubling circumferential wall tension had a minimal effect on total circumflex flow. When the slopes were extrapolated to zero, assuming linearity, a peak left ventricular pressure of 385 mmHg greater than coronary perfusion pressure would be required to reduce coronary flow to zero. The experiments were repeated in five additional animals but at different perfusion pressures from 40 to 160 mmHg. Higher perfusion pressures gave similar results but with even less effect of ventricular pressure on coronary flow or coronary conductance. These results argue for an active storage site for systolic arterial flow in the dilated coronary system. |
| | |
Authors:
|
F L Abel; R R Zhao; R F Bond |
Related Documents
:
|
11428534 - Lowering of blood pressure and coronary blood flow in isolated systolic hypertension. 3606544 - Comparison of cardiac and hemodynamic effects of platelet-activating factor-acether and... 6312814 - Myocardial adaptations to endurance exercise in aged rats. 6956474 - Verapamil: a selective antagonist of constrictor substances in dog coronary artery: imp... 15562664 - Pathophysiology of portal hypertension. 8599894 - Influence of extreme head rotations on brainstem auditory evoked potentials (baep). |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: The American journal of physiology Volume: 262 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1992 Jan |
Date Detail:
|
Created Date: 1992-02-25 Completed Date: 1992-02-25 Revised Date: 2007-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 0370511 Medline TA: Am J Physiol Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: H68-77 Citation Subset: IM |
Affiliation:
|
Department of Physiology, School of Medicine, University of South Carolina, Columbia 29208. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adenosine
/
pharmacology Animals Coronary Circulation* / drug effects Diastole Dogs Heart / physiology* Heart Ventricles Hemodynamics Male Perfusion Pressure Regression Analysis Systole |
| Chemical | |
Reg. No./Substance:
|
58-61-7/Adenosine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Myocardial depression produced by sustained tachycardia in rabbits.
Next Document: Oxygen free radicals affect cardiac and skeletal cell membrane potential during hemorrhagic shock in...