Background and Objectives：An abnormal Q wave, after an acute myocardial infarction, has been considered an indicator of myocardial necrosis. However, in some cases this Q wave partially or completely disappears during the evolution of the myocardial infarction. The clinical significance of Q wave regression remains to be established. Accordingly, this study was conducted to evaluate the relationship between Q wave regression, after an anterior wall acute myocardial infarction, and the improvements of the regional wall motion abnormality and left ventricular ejection fraction in echocardiography.
Subjcets and Methods：A total of 80 patients, who presented with a first anterior wall acute myocardial infarction, managed successfully with direct intervention, were divided into two groups according to the regression (group A) or presence (group B) of abnormal Q waves. Regression of an abnormal Q wave was defined as the disappearance of the Q wave and reappearance of the R wave ≥0.1 mV, in at least two of the I, aVL, and V1 to V6 leads.
Results：Of the 80 patients, 26 (32.5 %) had an abnormal Q wave regression within 12 months. The peak creatine kinase-MB activity was lower in group A than B (277.3±202.6 vs. 521.3±284.4 ng/dL, p<0.01). Group A had better left ventricular regional wall motion than group B in the initial echocardiograms. The degree of improvement of the left ventricular ejection fraction and regional wall motion between the initial and follow-up echocardiographies were significantly greater in group A than B.
Conclusion：Patients with an anterior wall acute myocardial infarction, showing Q wave regression, tended towards a smaller amount of necrotic myocardium and a significantly larger amount of stunned myocardium.
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