Circulation, Vol 56, 192-198, Copyright © 1977 by American Heart Association
MJ Cowley, JA Mantle, WJ Rogers, RO Russel Jr, CE Rackley and JR Logic
Two hundred-three patients had -echnetium 99m (stannous) pyrophosphate
myocardial scintigrams for the evaluation of chest pain and suspected acute
myocardial infarction. In addition to routine imaging at 60--90 minutes
after injection of the radio-pharmaceutical, the blood pool was imaged
immediately in each patient for comparison with routine anterior, left
anterior oblique, and left lateral views. Further delayed studies were
obtained when residual blood pool activity was identified. Seventy patients
had acute myocardial infarction by clinical, electrocardiographic, and
enzymatic (CK-MB) criteria. Sixty- five of these 70 patients with acute
infarction had positive myocardial scintigrams, with one technically
unsatisfactory study. Only four of the 70 patients had negative scintigrams
when imaged 18--72 hours after infarction in this study. Technically
satisfactory scintigrams were recorded in 125 patients without evidence of
infarction. Ninety-six had negative scintigrams at 60--90 minutes, while 19
patients (15%) had precordial activity at 60--90 minutes which was
identical in distribution to early blood pool images and cleared with
further delay. With these included, the true negative incidence was 92%.
Ten of 125 patients had false positive scintigrams; two had recent
cardioversion with resultant chest wall damage. The other eight patients
had previous infarction 1 1/2 to 72 months earlier and had akinetic
segments shown angiographically in the areas of the persistently positive
scintigrams. Myocardial scintigraphy correlates well with the presence of
other evidence of acute infarction, as well as with the absence of acute
infarction when residual blood pool activity is identified. False positive
scintigrams can occur following cardioversion and in patients with previous
myocardial infarction and resultant ventricular wall motion abnormalities.
ARTICLES
Technetium-99m stannous pyrophosphate myocardial scintigraphy. Reliability and limitations in assessment of acute myocardial infarction
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