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 t he dobutamine stress test and late improvement of function after acute Q wave myocardial infarction. Patients and design-70 patients were st udied a mean (SD) 8 (3) days after acute myocardial infarction with hi gh dose dobutamine-atropine stress echocardiography and a follow up ec hocardiogram at 85 (10) days. A score model based on 16 segments and f our grades was used to assess left ventricular function. Functional im provement 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. In tervention-Myocardial revascularisation was performed in 23 patients ( 33%) before follow up studies. Results-ST segment elevation occurred i n 40 patients (57%). Late functional improvement occurred in 35 patien ts (50%). Functional improvement was more common in patients with ST s egment 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 bas eline 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 seg ment elevation (1 . 39 (0 . 60) v 1 . 45 (0 . 47)). The accuracy of ST segment elevation for the prediction of functional improvement was si milar to that of low dose dobutamine echocardiography in patients with anterior infarction (80% v 83%) and in patients who underwent revascu larisation (78% v 83% respectively). Conclusion-In patients with a rec ent Q wave myocardial infarction, dobutamine-induced ST segment elevat ion is a valuable marker of myocardial viability particularly when the test is performed without or with suboptimal echocardiographic imagin g.