Briden K L, Weiss H R
Cardiovasc Res. 1981 Apr;15(4):206-13. doi: 10.1093/cvr/15.4.206.
The effects of a moderate sized arterio-venous shunt on the relationship of oxygen supply to consumption were studied on a regional basis in the dog left ventricle. Experiments were conducted on fourteen hearts, seven in control pentobarbital-anaesthetised, open-chest dogs and seven in dogs with an additional abdominal aorto-caval shunt. Regional oxygen extraction was determined by a microspectrophotometric method and coronary blood flow was measured with radioactive microspheres. The shunt, when opened, allowed cardiac output to increase by 50%. This was accomplished by increasing stroke volume, not heart rate. In control animals the subendocardium exhibited higher oxygen extraction, coronary flow, and oxygen consumption than did the subepicardium. There were no differences between base and apex. In open-shunt animals, subepicardial-subendocardial differences in extraction, flow and consumption were abolished. Subepicardial values for these in shunt animals were not different from the values obtained for the subepicardial values of controls. The subendocardium of shunt animals exhibited significant differences between base and apex for blood flow and oxygen consumption. There was a significant difference in subendocardial oxygen consumption between groups, the effect of the arterio-venous shunt being to reduce subendocardial consumption, especially in the apex, without reducing subepicardial oxygen consumption.
在犬左心室局部区域研究了中等大小动静脉分流对氧供与氧耗关系的影响。对14只心脏进行了实验，7只处于戊巴比妥麻醉、开胸的对照犬，7只处于另外有腹部主动脉 - 腔静脉分流的犬。通过显微分光光度法测定局部氧摄取，并用放射性微球测量冠状动脉血流量。分流开放时，心输出量增加50%。这是通过增加每搏量而非心率实现的。在对照动物中，心内膜下层的氧摄取、冠状动脉血流量和氧耗均高于心外膜下层。心底和心尖之间无差异。在开放分流的动物中，心外膜下层与心内膜下层在摄取、血流量和氧耗方面的差异消失。分流动物中心外膜下层的这些值与对照动物心外膜下层获得的值无差异。分流动物的心内膜下层在心底和心尖之间的血流量和氧耗存在显著差异。两组之间心内膜下层的氧耗存在显著差异，动静脉分流的作用是减少心内膜下层的氧耗，尤其是在心尖部，而不减少心外膜下层的氧耗。
