The artery of the atrioventricular node: an anatomic study based on 38 injection-dissections.

The origin and course of the artery of the atrioventricular node (AAVN) was studied in 45 anatomic specimens by the method of injection-dissection in 38 human hearts removed at medicolegal autopsies from black Senegalese subjects. Though sometimes double, the AAVN is classically solitary. Its coronary origin, which is always distal, occurred on the right side in the great majority of cases, at the level of the "U-turn of James", and on the left side at the level of the terminal portion of the circumflex a. At the level of Koch's triangle, its course is marked by a close relationship with the zone of attachment of the septal cusp of the right atrioventricular valve on the one hand, and with the orifice of the coronary sinus on the other. In cardiac surgery, respect for the area of Koch's triangle, the base of the interatrial septum and the region of the intersection of the cardiac sulci will reduce the risks of injury to the AAVN.