EPICARDIAL BRANCHES OF THE CORONARY-ARTERIES AND THEIR DISTRIBUTION IN THE RABBIT HEART - THE RABBIT HEART AS A MODEL OF REGIONAL ISCHEMIA

Background: The rabbit heart has been frequently used to study regiona l ischemia, but there is hardly any detailed information on the epicar dial branching of the coronary arteries, Therefore, we wanted to deter mine whether there is a constant branching pattern and how comparable this pattern is with the human heart. Methods: We investigated epicard ial branching of the coronary arteries in 30 adult rabbit hearts. For vessel visualisation, we used injections of Technovit, followed by cor rosion. Results: We found that there is not one constant pattern but r ather a bifurcation or a trifurcation of the arteria coronaria sinistr a (15 of 15 hearts), The left coronary artery is always the dominant a rtery; a vessel comparable to the human ramus interventricularis anter ior is rarely found in the bifurcation type. The ramus circumflexus is a constant but minor branch of the posterior or posterolateral divisi on and does not originate directly from the main stem of the left coro nary artery, as it does in humans, As a consequence, ligation of the l eft ramus interventricularis anterior leads to severe ischemic injury only where trifurcation exists (50% of our population), A ligation of the ramus circumflexus proximal to its origin produces a large postero lateral infarction in the bifurcation type (50% of our population). Co nclusions: Because a defined ischemic area is difficult to reproduce u nder these anatomical conditions, the rabbit heart may be a model only for regional ischemia if the investigator is knowledgeable about the distributions of the coronary arteries. (C) 1997 Wiley-Liss, Inc.