Comparison of patients with anterior wall healed myocardial infarction with and without exercise-induced ST-segment elevation.

To assess the extent of myocardial necrosis and ischemia in patients with anterior wall healed myocardial infarction depending on whether ST-segment elevation was present on precordial leads during exercise testing, 62 consecutive patients (49 men and 13 women, age [mean +/- SD] 56 +/- 11 years) with anterior wall infarcts were assessed with exercise technetium-99m (Tc-99m) methoxy-isobutyl-isonitrile single-photon emission computed tomography and quantification of the extent of necrosis and ischemia on polar maps: 22 patients had > or = 1 mm ST-segment elevation during exercise, and 40 did not. The extent of the necrosis in the anteroseptal (p = 0.001) and apical (p = 0.002) regions, the extent of ischemia in the lateral region (p = 0.003) on polar maps, and the frequency of ventricular aneurysm as shown by cardiac catheterization (p = 0.001) were significantly greater in patients with ST-segment elevation. In a multiple logistic regression model, both extent of necrosis in the anteroseptal region (odds ratio 10.8; 95% confidence interval 2.7 to 44.0) and extent of ischemia in the lateral region (odds ratio 7.25; 95% confidence interval 1.6 to 32.7) were associated with exercise-induced ST-segment elevation. These data suggest that ST-segment elevation in anterior infarctions is associated with wider necrosis in the anteroseptal and apical regions, with a wider extent of ischemia in the lateral region and a higher frequency of ventricular aneurysm. Consequently, it cannot be used as a marker of viability.