Acute Subendocardial Myocardial infarctioncolon; Its Detection by Tc-99m-Stannous Pyrophosphate Myocardial Scintigraphy

摘要

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 myocardial scintigraphy to detect the presence or absence of acute subendocardial myocardial necrosis. Three groups of patients were designated. Group A consisted of eight patients (13percnt;) who developed reduction of R-waves of more than 25percnt; 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 ldquo;poorly localizedrdquo; patterns. Group C consisted of 24 patients (39percnt;) 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 ldquo;poorly localizedrdquo; patterns. In four of the latter, the scintigrams were ldquo;persistently positiverdquo; several weeks to months after a previous myocardial infarct. Serial myocardial imaging will be necessary to identify such patients.