Automated identification of cardiac conduction tissue in L-TGV and Ebstein's anomaly.

The specialized cardiac conduction tissue was identified quickly and easily at operation in 2 patients with corrected transposition (L-TGV) and 1 with Ebstein's anomaly. In each of the former cases the tissue was located along the upper rim of the VSD, beneath the pulmonary outflow tract; in neither patient was there a disturbance in cardiac rhythm as a result of operation. In the patient with Ebstein's anomaly the bundle of His descended onto the ventricular septum more directly than was anticipated. There was only a transitory disturbance in atrioventricular conduction following tricuspid valve replacement. Accurate identification of the cardiac conduction tissue is a prerequisite to the safe repair of certain forms of complex congenital heart disease.