Intraoperative Low-dose Dobutamine Echocardiography Predicts the Post-pump Response of Dysfunctioning Myocardial Segments to Coronary Artery Bypass Grafting

BackgroundLow dose dobutamine echocardiography has recently been introduced for use in identification of viable myocardium in patients with acute myocardial infarction and prediction of the response of dysfunctioning myocardial segments to coronary angioplasty.The aim of this study was to evaluate whether this test could be used to predict the early response of dysfunctioning myocardial segments to coronary artery bypass grafting(CABG).MethodsWe studied in 23 patients with multi-vessel disease during CABG.Myocardial segments were monitored by intraoperative transesophageal echocardiography(TEE) in the transgastric short-axis view at papillary muscle level.The left ventricle was divided into five segments and sixty eight myocardial segments in 23 patients were analyzed.Percentage of systolic wall thickening(PSWT) was calculated in each segment for three timesat baseline(early after pericardiectomy)before bypass during dobutamine infusion(3-5ug/kg/min)and after seperation from cardiopulmonary bypass.Segments showing baseline PSWT 30% were considered normal and those <30% were dysfunctional.Segments showing an increase in PSWT 10% during dobutamine infusion were considered responders and those <10% nonresponders.ResultsAt baseline, 24(36%) of 68 segments had PSWT 30%(normal) and (4468%) had * .