Skip to main content
NCBI home page
The Journal of Clinical Investigation logoLink to The Journal of Clinical Investigation
. 1974 Dec;54(6):1462–1472. doi: 10.1172/JCI107894

Myocardial Blood Flow Distribution during Ischemia-Induced Coronary Vasodilation in the Unanesthetized Dog

Robert J Bache 1,2, Frederick R Cobb 1,2, Joseph C Greenfield Jr 1,2
PMCID: PMC301702  PMID: 4279928

Abstract

This study was designed to determine whether coronary vasodilation distal to a flow-limiting coronary artery stenosis could result in redistribution of myocardial blood flow to produce subendocardial underperfusion. Studies were performed in 10 awake dogs chronically prepared with electromagnetic flow-meters and hydraulic occluders on the left circumflex coronary artery. Regional myocardial blood flow was measured using radionuclide-labeled microspheres, 7-10 μm in diameter, injected into the left atrium. A 5-s coronary artery occlusion was followed by reactive hyperemia with excess inflow of arterial blood effecting 375±20% repayment of the blood flow debt incurred during occlusion. When, after a 5-s occlusion, the occluder was only partially released to hold arterial inflow to the preocclusion level for 20 s before complete release, the delayed reactive hyperemia was augmented (mean blood flow repayment = 610±45%, P < 0.01). This augmentation of the reactive hyperemia suggested that ischemia was continuing during the interval of coronary vasodilation when coronary inflow was at the preocclusion level. Measurements of regional myocardial blood flow demonstrated that endocardial flow slightly exceeded epicardial flow during control conditions. When arterial inflow was limited to the preocclusion rate during vasodilation after a 5-s total coronary artery occlusion, however, flow to the subepicardial myocardium was increased at the expense of underperfusion of the subendocardial myocardium. Thus, in the presence of a flow-limiting proximal coronary artery stenosis, ischemia-induced coronary vasodilation resulted in redistribution of myocardial blood flow with production of subendocardial ischemia in the presence of a net volume of arterial inflow which, if properly distributed, would have been adequate to prevent myocardial ischemia.

Full text

PDF
1462

Images in this article

1465Image
on p.1465
1466Image
on p.1466

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Alexander J. A., Sealy W. C., Greenfield J. C., Jr Improved technique for implanting electromagnetic flowmeter probes on the coronary artery. J Appl Physiol. 1969 Jul;27(1):139–140. doi: 10.1152/jappl.1969.27.1.139. [DOI] [PubMed] [Google Scholar]
  2. Armour J. A., Randall W. C. Canine left ventricular intramyocardial pressures. Am J Physiol. 1971 Jun;220(6):1833–1839. doi: 10.1152/ajplegacy.1971.220.6.1833. [DOI] [PubMed] [Google Scholar]
  3. Bache R. J., Cobb F. R., Greenfield J. C., Jr Effects of increased myocardial oxygen consumption on coronary reactive hyperemia in the awake dog. Circ Res. 1973 Nov;33(5):588–596. doi: 10.1161/01.res.33.5.588. [DOI] [PubMed] [Google Scholar]
  4. Becker L. C., Fortuin N. J., Pitt B. Effect of ischemia and antianginal drugs on the distribution of radioactive microspheres in the canine left ventricle. Circ Res. 1971 Feb;28(2):263–269. doi: 10.1161/01.res.28.2.263. [DOI] [PubMed] [Google Scholar]
  5. Buckberg G. D., Fixler D. E., Archie J. P., Hoffman J. I. Experimental subendocardial ischemia in dogs with normal coronary arteries. Circ Res. 1972 Jan;30(1):67–81. doi: 10.1161/01.res.30.1.67. [DOI] [PubMed] [Google Scholar]
  6. Buckberg G. D., Luck J. C., Payne D. B., Hoffman J. I., Archie J. P., Fixler D. E. Some sources of error in measuring regional blood flow with radioactive microspheres. J Appl Physiol. 1971 Oct;31(4):598–604. doi: 10.1152/jappl.1971.31.4.598. [DOI] [PubMed] [Google Scholar]
  7. Cibulski A. A., Lehan P. H., Hellems H. K. Myocardial collateral flow measurements in mongrel dogs. Am J Physiol. 1973 Sep;225(3):559–565. doi: 10.1152/ajplegacy.1973.225.3.559. [DOI] [PubMed] [Google Scholar]
  8. Cobb F. R., Bache R. J., Greenfield J. C., Jr Regional myocardial blood flow in awake dogs. J Clin Invest. 1974 Jun;53(6):1618–1625. doi: 10.1172/JCI107712. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Debley V. G. Miniature hydraulic occluder for zero blood flow determination. J Appl Physiol. 1971 Jul;31(1):138–139. doi: 10.1152/jappl.1971.31.1.138. [DOI] [PubMed] [Google Scholar]
  10. Downey J. M., Kirk E. S. Distribution of the coronary blood flow across the canine heart wall during systole. Circ Res. 1974 Feb;34(2):251–257. doi: 10.1161/01.res.34.2.251. [DOI] [PubMed] [Google Scholar]
  11. Edwards J. E. The value and limitations of necropsy studies in coronary arterial disease. Prog Cardiovasc Dis. 1971 Jan;13(4):309–323. doi: 10.1016/s0033-0620(71)80009-9. [DOI] [PubMed] [Google Scholar]
  12. Effler D. B., Sheldon W. C., Turner J. J., Groves L. K. Coronary arteriovenous fistulas: diagnosis and surgical management. Report of fifteen cases. Surgery. 1967 Jan;61(1):41–50. [PubMed] [Google Scholar]
  13. Griggs D. M., Jr, Tchokoev V. V., Chen C. C. Transmural differences in ventricular tissue substrate levels due to coronary constriction. Am J Physiol. 1972 Mar;222(3):705–709. doi: 10.1152/ajplegacy.1972.222.3.705. [DOI] [PubMed] [Google Scholar]
  14. KIRK E. S., HONIG C. R. AN EXPERIMENTAL AND THEORETICAL ANALYSIS OF MYOCARDIAL TISSUE PRESSURE. Am J Physiol. 1964 Aug;207:361–367. doi: 10.1152/ajplegacy.1964.207.2.361. [DOI] [PubMed] [Google Scholar]
  15. Moir T. W., DeBra D. W. Effect of left ventricular hypertension, ischemia and vasoactive drugs on the myocardial distribution of coronary flow. Circ Res. 1967 Jul;21(1):65–74. doi: 10.1161/01.res.21.1.65. [DOI] [PubMed] [Google Scholar]
  16. Moir T. W. Subendocardial distribution of coronary blood flow and the effect of antianginal drugs. Circ Res. 1972 Jun;30(6):621–627. doi: 10.1161/01.res.30.6.621. [DOI] [PubMed] [Google Scholar]
  17. OLSSON R. A., GREGG D. E. MYOCARDIAL REACTIVE HYPEREMIA IN THE UNANESTHETIZED DOG. Am J Physiol. 1965 Feb;208:224–230. doi: 10.1152/ajplegacy.1965.208.2.224. [DOI] [PubMed] [Google Scholar]
  18. PROVENZA D. V., SCHERLIS S. Coronary circulation dog's heart; demonstration of muscle sphincters in capillaries. Circ Res. 1959 May;7(3):318–324. doi: 10.1161/01.res.7.3.318. [DOI] [PubMed] [Google Scholar]
  19. Pauly T. J., Bittar N. Myocardial reactive hyperaemia responses in the dog after beta receptor block with propranolol. Cardiovasc Res. 1971 Oct;5(4):440–443. doi: 10.1093/cvr/5.4.440. [DOI] [PubMed] [Google Scholar]
  20. Pauly T. J., Zarnstorff W. C., Bittar N. Myocardial metabolic activity as a determinant of reactive hyperaemia responses in the dog heart. Cardiovasc Res. 1973 Jan;7(1):90–94. doi: 10.1093/cvr/7.1.90. [DOI] [PubMed] [Google Scholar]
  21. Roberts W. C. Coronary arteries in fatal acute myocardial infarction. Circulation. 1972 Jan;45(1):215–230. doi: 10.1161/01.cir.45.1.215. [DOI] [PubMed] [Google Scholar]
  22. Rowe G. G. Inequalities of myocardial perfusion in coronary artery disease ("coronary steal"). Circulation. 1970 Aug;42(2):193–194. doi: 10.1161/01.cir.42.2.193. [DOI] [PubMed] [Google Scholar]
  23. SALISBURY P. F., CROSS C. E., RIEBEN P. A. ACUTE ISCHEMIA OF INNER LAYERS OF VENTRICULAR WALL. Am Heart J. 1963 Nov;66:650–656. doi: 10.1016/0002-8703(63)90321-1. [DOI] [PubMed] [Google Scholar]

Articles from Journal of Clinical Investigation are provided here courtesy of American Society for Clinical Investigation

RESOURCES