Comparison of clinical features of non-Q wave and Q wave myocardial infarction.

The clinical spectrum and outcome of 119 patients with acute non-Q wave myocardial infarction (NQMI) were studied, in comparison with those of 354 patients with acute Q wave myocardial infarction (QMI). The patients with NQMI had a significantly higher incidence of preinfarction angina (73% vs 63%), previous myocardial infarction (43% vs 22%), multivessel disease (73% vs 51%), postinfarction angina (55% vs 21%), and recurrent myocardial infarction during follow-up for an average of 25 months (17% vs 8%). NQMI patients also had a lower rate of complication of pump failure and smaller infarct size estimated by peak creating phosphokinase (CPK) levels (1361 +/- 1243 vs 2711 +/- 1684 IU/L) than those with QMI. There was no difference in in-hospital mortality between the two groups (17% vs 17%). However, death due to cardiac rupture was exclusively noted in the QMI group. The present study suggests that NQMI is more unstable than QMI in the clinical course.