Spontaneous changes in regional wall motion abnormalities in acute myocardial infarction

The incidence of improvement in regional wall motion of segments with severe contractile abnormalities in the first 10 days after a first acute myocardial infarction (AMI) was assessed with serial gated blood pool scans in 95 patients who received standard medical therapy. Regional wall motion was quantitatively assessed as percent chord shortening in 4 segments in the anterior view and 4 segments in the 45 ° left anterior oblique view. Among 237 segments with ho more than 15% shortening (severely hypokinetic or akinetic [SH/A] segments), 59 (25%) improved at least 15% at 10 days, 166 (70%) did not change and 12 (5%) deteriorated by at least 15%. Among 91 patients who had SH/A segments, 37 (41%) had improvement in at least 1 SH/A segment (group 1) and 54 had no improvement in SH/A segments (group 2). Group 1 had a higher initial ejection fraction (EF) (50 ± 12%) than group 2 (45 ± 13%, p < 0.05). The changes in percent shortening of SH/A segments were compared with coronary anatomy in 37 patients who underwent coronary angiography. The 17 patients with 1-vessel coronary artery disease (CAD) had significantly improved wall motion (8.2 ± 13.4%, p < 0.005), in contrast to the 20 patients with multivessel CAD (1.8 ± 11.5%, difference not significant). Among patients with 1-vessel CAD, the improvement was greater in patients with right coronary or left circumflex artery disease (12.8 ± 14.4%) than in those with left anterior descending disease (4.1 ± 13.4%, p < 0.05). These data indicated that improved wall motion is seen in initially SH/A segments in 41% of AMI patients with akinesia. Patients with a higher initial EF and less severe CAD usually involving the inferoposterior wall are more likely to have improved wall motion in SH/A segments.