AJP - Heart and Circulatory Physiology, Vol 256, Issue 2 478-H485, Copyright © 1989 by American Physiological Society
Progressive change in collateral blood flow after coronary occlusion in conscious dogs
Y. T. Shen, D. R. Knight, D. R. Canfield, S. F. Vatner and J. X. Thomas Jr
Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Southborough, Massachusetts.
This study used a retrospective analysis of infarcted and salvaged tissue
samples to determine the patterns of blood flow changes (radioactive
microsphere technique) that occur within the area at risk during the first
24 h after coronary artery occlusion (CAO) in conscious dogs. With the
triphenyl tetrazolium chloride (TTC) technique, individual samples were
selected and included in either the infarcted (TTC-negative) or salvaged
(TTC-positive) group. The infarcted and salvaged samples were paired
according to blood flow levels of 0.1-0.2, 0.2-0.3, or 0.3-0.4 ml.min-1.g-1
at either 5 min, 1 h, 3 h, or 6 h after CAO. In tissue samples that were
salvaged, blood flow rose progressively, i.e., from 5 min to 1 h, from 1 to
3 h, from 3 to 6 h, and from 6 to 24 h. Blood flow to infarcted tissue rose
only in the longest interval, from 6 to 24 h after CAO. When blood flow
levels were less than 0.1 ml.min-1.g-1, virtually all the samples were
infarcted, whereas corresponding lesser amounts of infarction were observed
with increasing blood flow levels after CAO. Thus, in the conscious dog,
blood flow rises progressively to salvaged but not infarcted tissue within
the area at risk. Except for myocardium with blood flow levels less than
0.1 ml.min-1.g-1, the blood flow levels at any of the time points after CAO
could not be used to predict necrosis.
