NONUNIFORM DISTRIBUTION OF BLOOD FLOW AND GRADIENTS OF OXYGEN TENSION WITHIN THE HEART.
NONUNIFORM DISTRIBUTION OF BLOOD FLOW AND GRADIENTS OF OXYGEN TENSION WITHIN THE HEART.
复制标题
心脏内血流量和氧张力梯度的不均匀分布。
DOI：
10.1152/ajplegacy.1964.207.3.661
复制
发表时间：
1964
期刊：
影响因子：
--
通讯作者：
C. R. Honig
中科院分区：
文献类型：
--
作者：
E. Kirk;C. R. Honig
心肌组织压力从心外膜到心内膜升高，在心动周期的三分之一期间，更深层的心肌组织压超过脑室血压(21)。用仓库清除技术研究这种组织压力梯度对局部血流的影响。与浅部相比，深部的血流量至少低25%。在冠状动脉总流量保持不变的情况下，迷走性心脏停搏消除了组织压力梯度，同时将血流从浅层重新分配到深层。我们的结论是，组织压力的梯度，以及冠脉阻力的血管外成分，至少在一定程度上是跨壁血流不均匀的原因。利用氧阴极观察到与血流梯度平行的氧分压梯度；心外膜下的平均氧分压是心内膜下的两倍。氧分压梯度的大小足以决定有氧代谢中的跨壁梯度。
Myocardial tissue pressure increases from epicardium to endocardium, and in the deeper layers exceeds ventricular blood pressure during one-third of the cardiac cycle (21). The effect of this tissue pressure gradient on local blood flow was studied using the depot clearance technique. Blood flow was found to be at least 25% lower in the deep regions as compared with superficial ones. With total coronary inflow held constant, vagal arrest of the heart removed the tissue pressure gradient, and simultaneously redistributed flow from superficial to deeper layers. We conclude that the gradient in tissue pressure, and hence in the extravascular component of coronary resistance, is at least in part, the cause of the nonhomogeneous blood flow across the wall. By use of the oxygen cathode, a gradient of oxygen tensions was observed which paralleled the blood flow gradient; mean oxygen tension in the subepicardium averaged twice that in the subendocardium. The gradient in oxygen tension appears to be of sufficient magnitude to determine a transmural gradient in aerobic metabolism.