Prediction of improvement of ventricular function after first acute myocardial infarction using low-dose dobutamine stress echocardiography.

This study was performed to assess the prevalence of spontaneous improvement of regional left ventricular function in patients after acute myocardial infarction, and to evaluate the role of low-dose dobutamine stress echocardiography for its prediction. In 57 patients with a first acute myocardial infarction (thrombolysis, n = 27; Q-wave, n = 49), regional wall motion was evaluated with 2-dimensional echocardiography at rest, during a low-dose dobutamine stress test performed within 1 week after hospital admission, and at 3-month follow-up. Myocardial viability was considered if there was an improvement of > or = 1 grade in dyssynergic segments from rest to low-dose dobutamine infusion; recovery of regional function was defined as an improvement of > or = 1 grade between rest and follow-up echocardiograms. Wall motion score index decreased from rest to low-dose dobutamine echocardiography (1.46 +/- 0.29 to 1.39 +/- 0.30, p < 0.0001), and this change persisted at follow-up study (1.37 +/- 0.30). No differences were found between patients who did and did not undergo thrombolyis, or between those who had Q-wave and non-Q-wave infarction. At baseline echocardiography, 189 of 627 segments were dyssynergic (85 hypokinetic, 104 akinetic). Viability at low-dose dobutamine stress echocardiography was more frequent in hypokinetic than in akinetic segments (30 of 85 vs 12 of 104, odds ratio 4.18, 95% confidence interval [CI] 1.87 to 9.48).(ABSTRACT TRUNCATED AT 250 WORDS)