Technetium-99m-Pyrophosphate Myocardial Imaging in Patients with Atypical Chest Pain

Technetium-99m-pyrophosphate myocardial scintigrams may be utilized to help exclude the presence of acute myocardial infarcts in patients with atypical chest pain that are admitted to the coronary care unit. Our previous clinicopathologic correlates have suggested that 99mTc-pyrophosphate myocardial scintigrams are capable of identifying acute myocardial necrosis with 89% sensitivity and high specificity; this scintigraphic approach has an even higher sensitivity (one approaching 100%) in the identification of acute myocardial necrosis amounting to 3 g or more in weight when serial myocardial imaging is utilized and imaging is performed within the proper time frame (Table 13-1) [1–3]. When two 99mTc-pyrophosphate myocardial scintigrams are obtained in the first 24 hr to 5 days after acute myocardial infarction, one may be confident that serial negative 99mTc-pyrophosphate myocardial scintigrams exclude acute myocardial necrosis amounting to 3 g or more tissue with better than 95% sensitivity (Table 13-1)[1,2]. This, of course, requires optimal imaging technique and imaging within the appropriate time periods after the onset of symptoms (chapters 3 and 7) and some experience so that one may properly interpret the 99mTc-pyrophosphate myocardial scintigrams.