Three-dimensional analysis of infarct size reduction after administration of gallopamil in dogs

Several interventions have been shown to protect the ischemic myocardium from evolving to necrosis. However, three-dimensional evaluation of infarct size reduction using anatomical measurements is lacking. Therefore, Tc-99m labeled albumin microspheres were injected into the left atrium of 16 dogs, 1 min after coronary artery occlusion, to assess the hypoperfused zone. After 15 min, 8 dogs received, intravenously, gallopamil (Procorum) (Ga: 0.08 mg/k as a bolus + 0.2 mg/k/h for 6 h) and the remaining 8 dogs served as controls. At sacrifice (6 h), the left ventricle was cut into 3 mm slices, stained with triphenyltetrazolium chloride to delineate the size of infarction and autoradiographed to delineate the hypoperfused zone. Lateral reduction was calculated by the difference distance between hypoperfused zone and infarct size on the endocardium, mid-myocardium and epicardium; radial reduction was calculated by the difference of the transmural distance taken at mid-infarction and mid-hypoperfusion and the longitudinal reduction was calculated by the distance of the hypoperfused slices that did not infarct. With this technique it could be demonstrated that gallopamil reduced the size of infarction in all three dimensions.