Relation between ST segment elevation during dobutamine stress test and myocardial viability after a recent myocardial infarction

ObjectiveTo assess the relation between ST segment elevation during the dobutamine stress test and late improvement of function after acute Q wave myocardial infarction.Patients and design70 patients were studied a mean (SD) 8 (3) days after acute myocardial infarction with high dose dobutamine-atropine stress echocardiography and a follow up echocardiogram at 85 (10) days. A score model based on 16 segments and four grades was used to assess left ventricular function. Functional improvement was defined as a reduction of wall motion score ≥ 1 in ≥ 1 segments at follow up.InterventionMyocardial revascularisation was performed in 23 patients (33%) before follow up studies.ResultsST segment elevation occurred in 40 patients (57%). Late functional improvement occurred in 35 patients (50%). Functional improvement was more common in patients with ST segment elevation (68% v 30%, P < 0·005) and they had a higher mean (SD) number of improved segments at follow up (1·9 (2·2) v 0·5 (1·1), P < 0·005). The wall motion score index decreased between baseline and follow up in patients with ST segment elevation (1·54 (0·50) v 1·48 (0·43), P < 0·05) but not in patients without ST segment elevation (1·39 (0·60) v 1·45 (0·47)). The accuracy of ST segment elevation for the prediction of functional improvement was similar to that of low dose dobutamine echocardiography in patients with anterior infarction (80% v 83%) and in patients who underwent revascularisation (78% v 83% respectively).ConclusionIn patients with a recent Q wave myocardial infarction, dobutamine-induced ST segment elevation is a valuable marker of myocardial viability particularly when the test is performed without or with suboptimal echocardiographic imaging.