Significance of T-wave changes during early dobutamine stress echocardiography in patients with Q-wave acute myocardial infarction

The relation between T-wave changes and regional contraction during dobutamine stress echocardiography at low (5 to 10 μg/kg/min) and high (20 to 40 μg/kg/min) doses in 43 consecutive patients, early (7 ± 2 days) after first recent Q-wave acute myocardial infarction has been evaluated. T-wave changes detected in ≥2 infarct-related electrocardiographic leads during dobutamine infusion were defined as follow: (1) negative T waves becoming positive, (2) positive T waves becoming upright ≥2 mm, and (3) negative T waves becoming upright ≥2 mm from baseline. Wall motion score index (WMSI) was defined as the sum of the echocardiographic scores of 16 segments divided by total segments considered at baseline, and at low and peak doses of dobutamine. Patients were classified according to the absence or presence of dobutamine T-wave changes. Those without T-wave changes had a significantly higher WMSI at rest (1.68 ± 0.23 vs 1.50 ± 0.21; p