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

Objective-To 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 design-70 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 greater than or equal to 1 in greater than or equal to 1 segments at follow up. Intervention-Myocardial revascularisation was performed in 23 patients (33%) before follow up studies. Results-ST 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). Conclusion-In 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.