Markovitz L J, Savage E B, Ratcliffe M B, Bavaria J E, Kreiner G, Iozzo R V, Hargrove W C, Bogen D K, Edmunds L H
Department of Surgery, University of Pennsylvania, Philadelphia 19104.
Ann Thorac Surg. 1989 Dec;48(6):838-45. doi: 10.1016/0003-4975(89)90682-6.
In 28 Dorsett sheep, ligation of the distal homonymous (equivalent to human left anterior descending) and second diagonal coronary arteries produced a constant transmural infarct of 22.9% +/- 2.5% (mean +/- standard deviation) of the left ventricular mass. Serial left ventriculograms showed that within four hours the infarct segment expands, wall thickness decreases, and aneurysmal dilatation occurs and progresses over the next 60 days in all sheep. Epicardial ventricular point references indicated that adjacent noninfarcted myocardium participates in the formation of the aneurysm. Anatomy of the coronary vasculature was studied in 22 excised sheep hearts. In sheep, coronary arterial anatomy is remarkably constant. The left coronary artery provides all of the blood supply to the left ventricle and septum and only a small rim of both the anterior and posterior right ventricles. Cardiac veins from the left ventricle drain into the coronary sinus, which also receives the left azygos vein. Right ventricular veins drain separately. The essentially separate coronary circulations to the two ventricles, the paucity of coronary collateral circulation, and the consistent evolution of left ventricular infarcts into aneurysms are important advantages of the ovine model for both metabolic and ventricular mechanical studies of acute myocardial infarction and left ventricular aneurysm.
在28只多塞特羊中，结扎同名远端（相当于人类左前降支）和第二对角冠状动脉会导致左心室质量出现恒定的透壁梗死，占左心室质量的22.9%±2.5%（平均值±标准差）。连续的左心室造影显示，在4小时内梗死节段会扩张，壁厚度会减小，并且在接下来的60天内所有绵羊都会出现动脉瘤样扩张并进展。心外膜心室点参考表明相邻的非梗死心肌参与了动脉瘤的形成。对22个切除的羊心脏进行了冠状血管系统解剖研究。在绵羊中，冠状动脉解剖结构非常恒定。左冠状动脉为左心室和室间隔提供所有血液供应，仅为右心室前壁和后壁的一小部分边缘供血。来自左心室的心脏静脉汇入冠状窦，冠状窦还接收左奇静脉。右心室静脉单独引流。两个心室基本独立的冠状循环、冠状动脉侧支循环的匮乏以及左心室梗死向动脉瘤的一致演变，对于急性心肌梗死和左心室动脉瘤的代谢和心室力学研究而言，是绵羊模型的重要优势。
