Anatomy of coronary arteries in univentricular hearts and its surgical implications.

The coronary arterial anatomy in 26 univentricular hearts, its relation to the morphologic characteristics of the ventricles and rudimentary chambers, and its surgical implications were analyzed. All of the hearts except two had been operated on; 18 had septation with or without an extracardiac conduit and 6 had had palliative procedures. Twenty-one univentricular hearts with a left ventricular type main chamber had an anterior outlet chamber (17 left-sided subaortic, 3 right-sided subaortic and 1 right-sided subpulmonary). Right and left delimiting arteries outlined the outlet chamber in 16 hearts (76 percent). In 20 of the 21 hearts, large delimiting parallel branches of the right coronary artery course over the anterior wall of the heart; 13 of these vessels had been injured surgically with resultant ischemic myocardial necrosis. Five univentricular hearts did not have an outlet chamber; two had a left ventricular type main chamber and three had a morphologically right ventricular main chamber. Three of the five hearts had rudimentary pouches, located anteriorly in one and posteriorly in two. The two rudimentary pouches lying posteriorly were not outlined by delimiting arteries. Two of the five univentricular hearts without an outlet chamber also had injured coronary arteries. Thus, the identification of outlet chambers and rudimentary pouches in univentricular hearts is facilitated by the determination of coronary anatomy. The presence of major delimiting parallel branches over the usually favored ventriculotomy sites renders them vulnerable to surgical injury; such mishaps occurred in 15 of the 24 hearts that had either corrective or palliative operations.