Acute subendocardial myocardial infarction: its detection by Tc-99m stannous pyrophosphate myocardial scintigraphy.
Sixty-two patients hospitalized because of prolonged chest pain and initial electrocardiographic (ECG) changes of ST depression and T-wave inversion suggestive of acute subendocardial myocardial infarction were evaluated to determine the ability of Tc-99m-stannous pyrophosphate mycardial scintigraphy to detect the presence or absence of acute subendocardial myocardial necrosis. Three groups of patients were designated. Group A consisted of eight patients (13%) who developed reduction of R-waves of more than 25% or new Q-waves broader than 0.03 seconds; of these patients with acute transmural myocardial infarction, all had well-localized, abnormal scintigrams. Group B consisted of 30 patients with ECG changes and subsequent enzymatic documentation, including elevated serum creatine kinase-B levels as determined by radioimmunoassay, of the presence of acute subendocardial myocardial infarction. Of these, 27 had abnormal scintigrams, including 18 with well-localized patterns and nine with "poorly localized" patterns. Group C consisted of 24 patients (39%) with chest pain, but without enzymatic documentation of the presence of acute myocardial infarction (acute coronary insufficiency). Eight of these had abnormal scintigrams, including one with a well-localized pattern and seven with "poorly localized" patterns. In four of the latter, the scintigrams were "persistently positive" several weeks to months after a previous myocardial infarct. Serial myocardial imaging will be necessary to identify such patients.
D000328:Adult; D000368:Aged; D004796:Clinical Enzyme Tests; D004562:Electrocardiography; D004699:Endocardium; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000145:classification / Q000175:diagnosis / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging; D013667:Technetium; D014003:Tin Polyphosphates
D014003:Tin Polyphosphates; D013667:Technetium