Intraoperative ultrasonographic identification of coronary artery compression after an arterial switch procedure

A case is reported of a neonate with transposition of the great arteries, undergoing an arterial switch operation, in whom the cause for postbypass cardiac failure was diagnosed by intraoperative epicardial echocardiography. Obvious regional dyskinesia was seen by two-dimensional echocardiography in the posterolateral segments of the left ventricle, supplied by the circumflex coronary artery. After the switch procedure, the reimplanted circumflex artery ran between the aorta and the pulmonary artery. Lifting the pulmonary artery off the circumflex artery resulted in immediate improvement of regional myocardial function, which could be monitored on-line with echocardiography. Thus compression of the circumflex by the pulmonary artery was the cause for cardiac failure. On the basis of the echocardiographic information, immediate and successful surgical revision was performed. Intraoperative epicardial echocardiography has a unique diagnostic potential in the case of cardiac failure after cardiopulmonary bypass.