To demonstrate serial changes of left ventricular (LV) function during coronary artery bypass grafting surgery, transesophageal echocardiography (TEE) was used in 17 patients. The cross-sectional image of the left ventricle at the level of the papillary muscles was monitored, and was analyzed immediately in the operating room using a computer-assisted cine-memory function. Global LV function was evaluated by measuring LV end-diastolic and end-systolic area and computing the fractional area change (FAC). Segmental wall motion abnormalities (SWMA) were graded according to a scoring system. During the operative procedure before sternal closure, 5 patients showed SWMA with a simultaneous decrease in FAC to under 40%, and 9 patients showed SWMA without FAC depression. Two-thirds of new SWMA improved after myocardial revascularization. All 17 patients showed a change of interventricular septal movement at the end of the operation. FAC improved from a mean value (+/- SD) after intubation of 47.6 +/- 10.7% to a mean value after revascularization of 58.5 +/- 13.0% (p less than 0.05) and to a mean value at the end of the operation of 55.9 +/- 12.2% (p less than 0.05). Thus: 1) global and regional LV function improved immediately after myocardial revascularization with administration of inotropic agents; 2) a significant change of interventricular septal movement occurred after sternal closure; and 3) intraoperative TEE monitoring is a safe, simple, and effective method for evaluating LV global and regional function.