A study of 99mTc-MIBI myocardial imaging in experimental acute myocardial infarction

In order to evaluate the beneficial effects of early reperfusion on AMI, through canine models we investigated the advantage of 99mTc-MIBI myocardial imaging to quantify the size of myocardial infarction and the amount of salvaged myocardium after reperfusion. Six dogs underwent a permanent coronary artery occlusion, and other six coronary occlusions were followed by reperfusion. 99mTc-MIBI was injected during occlusion and imaging performed 1 hour later. All animals were killed after the second imaging performed one week later. In the initial imaging, all the dogs had similar sizes of scintigraphic perfusion defect in two groups (27.8% +- 2.9% vs 33.9% +- 4.0%). In the second imaging, the size of the defect, however, was significantly larger in the permanent occlusion group than that in the reperfusion group (24.4% +- 2.0% vs 13.2% +- 3.6%), and the percentage of salvaged myocardium was greater in the latter (58.0% +- 8.9%) than in the former (10.5% +- 5.3%). The size of perfusion defect in second imaging correlated well with the pathologic infarct size (r = 0.72)