Evaluation of the effects of different cardioplegic techniques on left ventricular function during coronary artery bypass surgery using transesophageal echocardiography.

Fifty consecutive patients undergoing coronary artery bypass grafting surgery were studied to evaluate the effect of intermittent anterograde cold cardioplegia (IACCH) and intermittent combined anterograde-retrograde cold cardioplegia (IRCCN) on left ventricular function using transesophageal echocardiography. Global function did not significantly change in both groups, but significantly more inotropes were required in IACCH. Newly developed abnormalities of regional wall motion after cardiopulmonary bypass, which were indicative of ischemic myocardium, were detected in the segments supplied by the right coronary artery in both groups (IACCH, 20%; IRCCN, 16%), by the left circumflex coronary artery only in IACCH (12%) and by the left anterior descending coronary artery only in IRCCN (12%). It is concluded that although global evaluation of left ventricular function did not show any significant change after IACCH and IRCCN under routine management, analysis of abnormalities of regional wall motion provided specific information. In both groups, complete protection of the myocardium was not achieved, and the characteristics of poorly protected areas were dependent on the difference in the two methods. Myocardium supplied by the right coronary artery seemed to be particularly vulnerable, and a special effort to protect these segments is mandatory for a successful outcome.