Aortic root hypothermic, hyperkalemic cardioplegic perfusion has been shown to preserve ventricular function during open heart surgery. However, significant coronary artery stenoses may prevent adequate perfusion of myocardial regions distal to the lesions, leading to intraoperative ischemia and damage. The purpose of this study was to evaluate for the first time in human patients the use of intraoperative contrast cardioplegic echocardiography for identifying potentially jeopardized myocardial regions as defined by cardiac catheterization. Forty-two patients, 23 men and 19 women, aged 28 to 83 years (mean 56.7 +/- 2), who had undergone cardiac catheterization and coronary arteriography, underwent open heart surgery; 30 had coronary artery disease. Echocardiograms of the left ventricle, performed on the open heart in the papillary muscle short-axis plane during routine aortic root cardioplegia were divided into three regions according to the coronary anatomy: septal (left anterior descending artery), anterolateral (left circumflex) and inferoposterior (right coronary artery). Intraoperatively, myocardial segments at greatest potential ischemic risk were identified by several findings alone or in combination: lack of spontaneous contrast and delayed whiting out or persistent fine fibrillation. The ability of intraoperative echographic interpretation to identify high risk segments based on preoperative catheterization findings was excellent. Thus, the sensitivity of cardioplegic contrast echocardiography for predicting significant (greater than 70% stenosis) coronary lesions was 96, 100 and 58% for left anterior descending, left circumflex and right coronary artery regions, respectively. Specificity was 94, 78 and 100% for anterior descending, circumflex and right coronary artery regions, respectively. Overall sensitivity and specificity for all regions was 82 and 92%, respectively. Importantly, the echocardiogram was most helpful in observing septal region perfusion.(ABSTRACT TRUNCATED AT 250 WORDS)