POSTERIOR SINUS NODE ARTERY AND ACCESSORY ATRIOVENTRICULAR NODE ARTERY ARISING BY A COMMON ORIGIN - A CASE-REPORT

We describe herein a rare and hitherto not reported variation, found i n a Japanese male cadaver, in which a posterior sinus node (SN) artery and an accessory atrioventricular node (AN) artery originate from a c ommon trunk branching from the posterior segment of the circumflex art ery. After arising in this manner, the posterior SN artery passed in a clockwise direction around the posterior, lateral, and finally anteri or wall of the left atrium to the sinus venosus, giving off a branch t o the SN from posteriorly. The accessory AN artery coursed in a counte rclockwise direction on the posterior wall of the left atrium as far a s the crux of the heart, where it bent anterosuperiorly and continued within the interatrial septum. It entered the AN from superiorly and, crossing deep to the principal AN artery, reached the inferior and sup erficial portion of this node. It could be considered that the accesso ry AN artery in this study is a modified version of arteries entering and coursing in the interatrial septum? as exemplified by Kugel's anas tomotic artery. (C) 1998 Wiley-Liss, Inc.