Kaul S, Glasheen W P, Oliner J D, Kelly P, Gascho J A
Department of Medicine, University of Virginia School of Medicine, Charlottesville 22908.
J Am Coll Cardiol. 1991 May;17(6):1403-13. doi: 10.1016/s0735-1097(10)80154-8.
The relation between anterograde blood flow through a coronary artery and the size of the perfusion bed it supplies is not known. Accordingly, the left circumflex coronary artery was cannulated and perfused with arterial blood in 12 open chest mongrel dogs. In Group I dogs (n = 7), the goal was to correlate the size of the perfusion bed with the magnitude of anterogradely derived myocardial blood flow. The size of the perfusion bed was measured with use of two-dimensional myocardial contrast echocardiography, whereas anterograde myocardial blood flow was determined by injecting radiolabeled microspheres directly into the artery. In Group II dogs (n = 5), the goal was to study the effects of altering coronary blood flow on both anterogradely and collateral vessel-derived myocardial flow within the perfusion bed. In these dogs, microspheres were injected directly into both the coronary artery and the left atrium at each flow rate. In Group I dogs, the left circumflex perfusion bed size, as defined by myocardial contrast echocardiography, decreased at lower anterograde myocardial blood flow rates. The change in perfusion bed size occurred at the lateral zones. There was a linear relation between the normalized perfusion bed size and the normalized anterograde myocardial blood flow: y = 0.45x + 54.2 (p less than 0.001, r2 = 0.77). These results were substantiated in Group II dogs, in which the size of the perfusion bed was approximated with use of radiolabeled microspheres. The size of the perfusion bed was most affected when anterograde myocardial blood flow decreased to less than approximately 33% of normal. At the lowest flow rates, there was a linear relation between anterograde blood flow versus the fraction of the left circumflex flow derived anterogradely: y = 2.41x + 0.22 (p less than 0.001, r2 = 0.90). The lower the level of anterograde flow, the greater was the blood flow derived from remote vessels. It is concluded that the size of the area perfused by a coronary artery is significantly influenced by the magnitude of anterograde blood flow through that artery. These findings may have important implications in experimental and clinical models of myocardial ischemia.
冠状动脉的顺行血流与其所供应的灌注床大小之间的关系尚不清楚。因此，在12只开胸杂种犬中对左旋冠状动脉进行插管并灌注动脉血。在第一组犬（n = 7）中，目标是将灌注床大小与顺行性心肌血流的大小相关联。灌注床大小通过二维心肌对比超声心动图测量，而顺行性心肌血流通过将放射性标记微球直接注入动脉来确定。在第二组犬（n = 5）中，目标是研究改变冠状动脉血流对灌注床内顺行性和侧支血管衍生的心肌血流的影响。在这些犬中，在每个血流速度下将微球直接注入冠状动脉和左心房。在第一组犬中，如通过心肌对比超声心动图所定义的，左旋冠状动脉灌注床大小在较低的顺行性心肌血流速度下减小。灌注床大小的变化发生在外侧区域。标准化灌注床大小与标准化顺行性心肌血流之间存在线性关系：y = 0.45x + 54.2（p < 0.001，r2 = 0.77）。这些结果在第二组犬中得到证实，在该组犬中使用放射性标记微球估算灌注床大小。当顺行性心肌血流降至正常的约33%以下时，灌注床大小受影响最大。在最低血流速度下，顺行血流与左旋冠状动脉顺行血流分数之间存在线性关系：y = 2.41x + 0.22（p < 0.001，r2 = 0.90）。顺行血流水平越低，来自远处血管的血流就越大。结论是，冠状动脉所灌注区域的大小受到通过该动脉的顺行血流大小的显著影响。这些发现可能对心肌缺血的实验和临床模型具有重要意义。
