Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Pathophysiology of technetium-99m stannous pyrophosphate and thallium-201 scintigraphy of acute anterior myocardial infarcts in dogs

Journal Article · · J. Clin. Invest.; (United States)
DOI:https://doi.org/10.1172/JCI108421· OSTI ID:7313417

In 17 dogs with acute myocardial infarcts produced by ligation of the proximal left anterior descending coronary artery, a comparative study was made of myocardial scintigrams obtained with technetium-99m stannous pyrophosphate (/sup 99m/Tc-PYP) and thallium-201 (/sup 201/Tl), tissue levels of /sup 99m/Tc-PYP and /sup 201/Tl uptake, histopathologic alterations, and regional myocardial perfusion measured with radioactive microspheres. Nine of the 10 hearts examined histologically had transmural infarcts with outer peripheral, inner peripheral, and central zones characterized by distinctive histopathologic features. A progressive reduction in myocardial blood flow was demonstrated between normal myocardium and the centers of the infarcts, and correlated well with progressive reduction in /sup 201/Tl uptake in the same regions. Marked /sup 99m/Tc-PYP concentration occurred in areas with partial to homogeneous myocardial necrosis and residual perfusion located in the outer peripheral regions of the infarcts. The latter areas also were characterized by the presence of muscle cell calcification. The patterns of distribution of /sup 99m/Tc-PYP and /sup 201/Tl explained the filling defects on /sup 201/Tl myocardial scintigrams and the doughnut patterns on /sup 99m/Tc-PYP myocardial scintigrams in dogs with transmural infarcts. One dog with a subendocardial infarct had a small homogeneous area of activity on the /sup 99m/Tc-PYP myocardial scintigram; and showed marked uptake of /sup 99m/Tc-PYP in subendocardial areas of extensive necrosis and calcification still receiving some coronary perfusion. Thus, the data indicate that the status of regional myocardial perfusion is a key determinant for the occurrence of distinctive patterns of myocardial necrosis and for the scintigraphic detection of acute myocardial infarcts with /sup 99m/Tc-PYP and /sup 201/Tl.

Research Organization:
Univ. of Texas Health Science Center, Dallas
OSTI ID:
7313417
Journal Information:
J. Clin. Invest.; (United States), Journal Name: J. Clin. Invest.; (United States) Vol. 57:6; ISSN JCINA
Country of Publication:
United States
Language:
English