Comparison of dobutamine infusion and exercise during radionuclide ventriculography in the risk stratification after acute myocardial infarction.

Forty-eight patients with acute myocardial infarction were subjected to radionuclide ventriculography during exercise and dobutamine infusion after a mean duration of 25 +/- 18 days following acute myocardial infarction. The results were compared and correlated with coronary angiography. Two patterns of abnormal response of radionuclide ventriculography were identified: (1) a worsening of the baseline wall motion abnormality confined to the infarcted area, and (2) fresh regional wall motion abnormalities in areas with normal motion at rest. Of 44 patients with significant coronary artery lesions (> or = 70% diameter stenosis), 18 had single vessel disease and 26 had multivessel disease. Dobutamine and exercise radionuclide ventriculography identified 23 and 21, respectively, of 26 multivessel disease patients yielding sensitivities of 88% and 80%. Seven of 18 single vessel disease patients showed a worsening of baseline wall motion abnormality of infarct area on dobutamine infusion radionuclide ventriculography. Subgroup analysis of coronary angiograms of single vessel disease revealed that 10 of 18 patients had subtotal occlusion of infarct-related artery supplying a hypokinetic area and the rest had a totally occluded coronary artery supplying an akinetic area. Dobutamine infusion and exercise radionuclide ventriculography detected 7 and 6 of these 10 patients implying the presence of jeopardized myocardium in infarcted/peri-infarct area. Dobutamine stress radionuclide ventriculography is an acceptable alternative to exercise testing to stratify risk following acute myocardial infarction.