Technetium-99m-Pyrophosphate Myocardial Imaging in Acute Myocardial Infarction

The recognition of acute myocardial infarcts is not always easily accomplished. Infarct recognition is especially difficult using electrocardiography in individuals who had previous myocardial infarcts, those with left bundle branch block, those who have been cardioverted, and those with acute non-transmural (subendocardial) myocardial infarcts. Even the most sophisticated enzymatic techniques presently available have certain limitations in identifying the presence of absence of acute myocardial infarcts in patients including: (1) there is a temporal dependency in the ability of various enzyme markers to detect acute myocardial infarcts, and (2) certain clinical settings preclude using traditional enzyme techniques (including creatine kinase — MB isoenzyme) for infarct recognition and to be emphasized in this regard is the perioperative and postoperative setting after coronary artery revascularization. Therefore, it is important to have additional relatively noninvasive means that allow infarct detection, localization and provide some estimate of the size of the lesion.