SIGNIFICANCE OF Q-WAVE DISAPPEARANCE IN THE CHRONIC PHASE FOLLOWING TRANSMURAL ACUTE MYOCARDIAL-INFARCTION

The mechanism and prognostic implications of Q wave regression following transmural acute myocardial infarction (AMI) were assessed in 54 patients. Of these subjects, 14 lost their Q waves. Exercise myocardial thallium-201 (Tl-201) scintigraphy and two-dimensional echocardiography were performed before the patients were discharged from hospital. Two-dimensional echocardiography and electrocardiography were simultaneously repeated about 18 months after AMI. Both the relative Tl-201 activity in the infarcted area and the improvement of echocardiographic wall motion index were higher in patients who had lost their Q waves than in those with retained Q waves (70 +/- 14% vs 58 +/- 13%, p < 0.01; 5.2 +/- 3.0 vs 2.0 +/- 3.4, p < 0.01, respectively). The prevalence of post-infarction angina pectoris was significantly higher in the former (29% vs 0%, p < 0.01). We concluded that remnants of viable myocardial muscle might be responsible for Q wave regression following transmural acute myocardial infarction, and the prevalence of post-infarction angina pectoris was high among these patients.