To assess the effects of coronary revascularization on viable but noncontractile myocardium, we examined 21 patients with a documented anterior acute myocardial infarction who had a significant improvement in wall motion abnormality evaluated by two-dimensional echocardiography in the infarct-related artery in response to low-dose dobutamine infusion. All patients had a significant residual stenosis in the infarct-related artery. In response to low-dose dobutamine, there was a marked improvement in contractility in the infarct-related area segments and this was reflected by a decrease in echocardiographic score index from 1.5 ± 0.15 to 1.09 ± 0.08 (p = 0.0001). Of these 21 patients, 13 underwent successful revascularization: 10 had percutaneous transluminal coronary angioplasty (PTCA) and three had coronary artery bypass grafts (CABG) (group I). Eight patients received medical therapy only (group II). At 40 ± 15 days of follow-up, both groups had improvement in their segmental wall motion abnormalities. However, the improvement in group I was greater than that in group II, 1.1 ± 0.13 and 1.35 ± 0.1, respectively (p = 0.0002). We conclude that: (1) low-dose dobutamine infusion may identify viable but noncontractile myocardium in patients with acute myocardial infarction and (2) in these patients revascularization causes a greater improvement in left ventricular function over time when compared with a nonrevascularized group.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine