Since post-acute myocardial infarction (AMI) Q waves may disappear independent of reinfarction or development of left bundle branch block, the relation between the presence of Q waves and segmental asynergy was assessed in 58 patients with initial Q waves after first AMI. Two-dimensional (2-D) echocardiograms and electrocardiograms were recorded 1 year later. By electrocardiography, 28 had anterior and 25 inferior AMI. At 1 year Q waves had disappeared in 12 of 53 patients (23%): 5 with anterior and 7 with inferior AMI. Segmental asynergy, however, was present in 9 of these 12 patients, although dyskinesia was absent. Presence of Q waves at 1 year (41 patients) was always associated with segmental asynergy. Wall motion score, based on degree of segmental asynergy, was higher in the 41 patients with Q waves compared with patients in whom Q waves disappeared (7.8 +/- 4.4 vs 2.7 +/- 1.9, p less than 0.001). In patients with anterior AMI the number of Q waves at 1 year and the grade of asynergy were correlated. Segmental dyskinesia was rare in patients with inferior AMI (1 of 25) but was common in those with anterior AMI (18 of 28), and was consistently present in patients with more than 2 anterior Q waves.