title: Electrocardiographic changes during dobutamine stress testing in patients with recent myocardial infarction: relation with residual infarct artery stenosis and contractile recovery.
abstract: OBJECTIVE
  The identification of viable but jeopardized myocardium after acute myocardial infarction (AMI) is of great importance for selecting patients who could benefit from a revascularization procedure. The aim of the study was to determine the accuracy of the dobutamine stress electrocardiogram (ECG) 1) for detecting significant stenosis of the infarct-related artery and 2) for predicting the occurrence of contractile recovery.
  
  
  RESULTS
  Ninety-four patients underwent dobutamine stress ECG and quantitative angiography within the first week after AMI. A follow-up resting echocardiogram was obtained in all patients at 1 month. Significant stenosis of the infarct-related artery was detected in 76 patients and functional recovery occurred in 56 patients. Dobutamine stress induced ST-segment elevation in 44 patients, ST-segment depression in 17 and T-wave normalization in 34. Increase in QT dispersion and dobutamine ST elevation were more sensitive than chest pain and ST-segment depression (79% and 53% vs. 24% and 17%, respectively; p<0.05) for detecting significant infarct-related artery stenosis. Four independent variables were selected for predicting contractile recovery: > or = 20 ms increase in QT dispersion from baseline to low-dose dobutamine (p = 0.00016), dobutamine-induced ST-segment elevation (p = 0.0009), elective angioplasty of the infarct-related artery (p = 0.001) and T-wave normalization (p = 0.005).
  
  
  CONCLUSIONS
  The analysis of predischarge dobutamine stress ECG is useful for predicting residual stenosis of the infarct-related artery and contractile recovery in the affected area. QT dispersion changes during the test are the most accurate parameter.
authors.affiliation: Department of Cardiology, University Hospital, Liège, Belgium.
authors.forename: Patrizio
authors.initials: P
authors.lastname: Lancellotti
authors.forename: Jean Bruno
authors.initials: JB
authors.lastname: Mipinda
authors.forename: Luc A
authors.initials: LA
authors.lastname: Pierard
mesh_terms: D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000175:diagnosis*; D025401:Echocardiography, Stress / Q000379:methods*; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D009203:Myocardial Infarction / Q000503:physiopathology* / Q000534:rehabilitation; D015203:Reproducibility of Results