Background and objective: The denomination non-Q-wave myocardial infarction ranges from small infarcts without scintigraphic abnormalities to severe and extensive necrosis with scintigraphic criteria of transmurality. The aim of the present study was to evaluate the severity and localization of necrosis in patients with non-Q-wave myocardial infarct, by myocardial perfusion single photon emission computed tomography (SPECT).
Patients and method: We evaluated 206 patients with non-Q-wave myocardial infarct consecutively studied by myocardial perfusion 99mTc-tetrofosmin SPECT. Severity and localization of perfusion defects at stress and rest were analyzed.
Results: Rest SPECT was normal in 53 patients (26%) and in 41 patients (20%) at least one segment with scintigraphic criteria of transmurality (uptake absence) was observed. Perfusion defects were more frequently localized in inferior and lateral regions. Stress-rest reversibility in peri-infarct regions was observed in 68.9% of patients, and reversibility at a distance was observed in 30% of patients.
Conclusions: Myocardial perfusion SPECT is a useful technique for the evaluation of the localization, extension and transmurality of non-Q-wave myocardial infarction, and the residual peri-infarction ischemia and ischemia at a distance of the necrosis.