Effects of tocainide on ventricular fibrillation threshold. Comparison with lidocaine

In truncus arteriosus communis, as in other anomalies of conotruncal development, the coronary arterial anatomy not only differs from that found in the normal heart but also is subject to unpredictable variations. A consistently distinctive pattern was found in roughly two thirds of 31 cases, a frequency approximating that with which a distinctive coronary arterial pattern occurs in complete transposition of the great vessels. Surgical injury to a major coronary artery was identified in 2 of the 30 hearts from patients with truncus arteriosus communis who died in the early postoperative period. Of particular significance are large branches of the right coronary artery crossing the upper anterior surface of the right ventricle to supply the anterobasal surface of both ventricles and the upper part of the interventricular septum. These arteries are at special risk in surgical procedures utilizing a conduit anastomosed to a right ventriculotomy.