BACKGROUND: Intraoperative low dose dobutamine test with transesophageal echocardiography may offer a simple, cost effective and widely available mean of detecting contractile reserve in coronary artery disease. The purpose of this study was to determine the effect of low dose dobutamine infusion on ventricular function in patients undergoing coronary artery bypass graft and to predict the post-pump response of dysfunctional myocardial segments to surgical revascularization. METHODS: This study was performed in 23 patients undergoing coronary artery bypass graft. After transesophageal echocardiographic images of transgastric left ventricular short axis view at mid-papillary muscles level were obtained, the percentage of systolic wall thickening(PSWT) was evaluated. The ejection fraction by modified Simpson's method and hemodymic changes were measured simultaneously. RESULTS: The clinical accuracy of intraoperative low dose dobutamine test for PSWT was followed; Sensitivity-76%, specificity-94.7%, positive predictive value-95%, negative predictive value-75% and overall accuracy-84.1%. Ejection fraction increased from 49.0 13.1% to 56.3 11.5%(dobutamine infusion) and 59.5 12.1%(post-pump) significantly(P<.05). During dobutamine infusion and post-pump, cardiac index increased significantly(P<.01). CONCLUSIONS: Intraoperative low dose dobutamine by transesophageal echocardiography is a potentially useful test for prediction of the post pump response of regional systolic function and global ventricular function to coronary revascularization.