Characterization of non-Q wave infarction by radioisotopic methods

The syndrome of "subendocardial infarction" "or" non Q-wave infarction", which has been defined only in terms of the presence of (ECG) electrocardiographic evidence of necrosis, has been shown to be poorly correlated with anatomical and pathomorphological findings. In a large number of patients who had been diagnosed as having this commonly described entity, the usefulness of a multiparametric approach was evaluated. The proper assessment of such patients may necessitate flow studies with T1-201, which is, however, a marker with known limitations; labelled microspheres; or Rb-82, a generator-produced positron emitter. Metabolic studies using fluoro-F-18-deoxyglucose or C-11 palmitate will detect impairment of fatty acid oxidation and residual glucose metabolism; wall motion studies will demonstrate functional impairment to a variable extent. The presence or absence of Q-waves does not distinguish between transmural and subendocardial infarction. The size and location of ST-T wave changes do not indicate the site of infarction. Patients with this syndrome exhibit a wide spectrum of wall motion abnormalities and usually have diffuse coronary lesions. Since conventional clinical investigations cannot be used to predict the presence and extent of necrosis, or its exact location, the studies performed should be directed toward the appropriate evaluation of perfusion and metabolic patterns. This emphasizes the important point that clinicians may investigate this syndrome by the use of the proper approach.