Perfusion of the canine interventricular septum: Significance of right coronary artery supply

The perfusion of the canine interventricular septum was studied by the method of postmortem injection of a colored barium-gelatin mass with radiographic and histologic examination of specimens. These studies demonstrated distributions of the right and left coronary arteries similar to those described by other workers with two significant exceptions. First, radiographically visible vessels were seen coursing from the right coronary artery to the upper portion of the interventricular septum. Second, histologic demonstration of right coronary artery perfusion to the upper interventricular septum (in some cases including the specialized conduction tissue contained therein), and intercoronary anastomoses within the interventricular septum were observed. Right coronary artery supply to the septum was more frequent and of greater magnitude than previously described. These results may explain certain data pertaining to experimental myocardial ischemia and to coronary arteriography and suggest a functionally important role for the right coronary artery supply to the canine septum. These considerations render it imperative that the vascular supply to the canine interventricular septum be considered in experiments involving the coronary circulation and the septum. Some investigations demand a single vascular supply to a particular region of interest. The canine interventricular septum can no longer be considered in this category.