[Arterial vascularization of the sino-auricular node of the heart in dogs]

In order to study the arterial blood supply of the sinus atrial node in the Dog, the authors have performed the post-mortem injection of the arterial branches going to this node. They observed 65 cases and they came to the following conclusions: in 31 cases (47.7%) the sinus atrial node is supplied by the artery of the sinus atrial node and by the anterior atrial artery, branch of the circumflex; in 20 cases (30.8%) besides the two arteries already mentioned there was also the anterior branch from the first portion of the right coronary artery; in 13 cases (20%) the sinus atrial node was exclusively supplied by the artery of the sinus atrial node and in one case (1.5%) it was supplied only by the first anterior atrial branch of the circumflex artery. Their findings are different from those of other authors and they attribute the failure in provoking experimental ischemia of the sinus atrial node in the Dog, to the rich blood supply of this node and to the different origins of the vessels supplying it.