Value of intraoperative left ventricular microbubbles detected by transesophageal two-dimensional echocardiography in predicting neurologic outcome after cardiac operations

To determine whether the presence or absence of left ventricular (LV) intracavitary microbubbles during cardiac surgery predicts neurologic sequelae, 82 patients undergoing cardiac surgery were studied using transesophageal 2-dimensional (2-D) echo-cardiography. Cross-sectional images were recorded just before and immediately after cardio-pulmonary bypass and stop frames were reviewed for the presence of microbubbles, rated as: 0 = absent, 1 = fewer than 5/frame, 2 = 10 to 25/frame, 3 = too numerous to count. Microbubbles were detected after cardiopulmonary bypass in 34 patients (41%) and found more often in valvular or other intracardiac manipulations than in coronary revascularization, 30 of 40 vs 4 of 42, respectively (p