technetium-tc-99m-gluceptate and Myocardial-Infarction

Scintigraphy with 99mTc -Sn-glucoheptonate permits the determination of the focus of transmural myocardial infarction at the earliest stages of the disease (from three hours to the fifth day of the disease) whereas scintigraphy with 99mTc -Sn-pyrophosphate makes it possible to follow-up the zone of transmural infarction from Day 2 through Day 7-10. Both methods fail to provide enough information to diagnose non-transmural myocardial infarction. A comparative evaluation of the nature of glucohepatonate and pyrophosphate incorporation in the myocardium of patients with unstable angina is suggestive of the severity of ischemic changes in the myocardium.

Topics: Adult; Aged; Angina Pectoris; Humans; Middle Aged; Myocardial Infarction; Organotechnetium Compounds; Polyphosphates; Radionuclide Imaging; Sugar Acids; Technetium; Technetium Tc 99m Pyrophosphate; Time Factors; Tin Polyphosphates

Topics: Adult; Aged; Diphosphates; Electrocardiography; Humans; Middle Aged; Myocardial Infarction; Organotechnetium Compounds; Sugar Acids; Technetium; Time Factors; Tomography, Emission-Computed

An isolated-heart preparation has been adapted to permit rapid evaluation of, and imaging by, myocardial tracers. The rabbit heart provided a mass large enough for imaging and serial biopsies. Coronary arteries could be selectively ligated and provided landmarks for epicardial ST segment mapping. Uptake ratios between a tissue sample and normal myocardium (T/N), obtained using Tc-99m glucoheptonate as an infarct-seeker, increased with duration of the ischemic period, which was followed by reflow. After 25 min of occlusion the T/N was 4.5; after 40 min T/N = 6; after 60 min T/N = 8; and after 120 min T/N = 19. This well-controlled adjunct to in vivo studies allows evaluation of myocardial imaging agents without interfering with systemic effects or blood and tissue background. Functional and structural changes can be sequentially measured and correlated with the localization of various radiopharmaceuticals.

Topics: Animals; Coronary Disease; Disease Models, Animal; In Vitro Techniques; Male; Myocardial Infarction; Organotechnetium Compounds; Rabbits; Radionuclide Imaging; Sugar Acids; Technetium