White C W, Marcus M L, Abboud F M
Circ Res. 1977 Apr;40(4):342-7. doi: 10.1161/01.res.40.4.342.
We assessed segmental distribution of blood flow to the right atrium and the region of the sinoatrial node using micropheres (7-10 mum) in 20 anesthetized dogs. Mean right atrial flow averaged 83+/-7 (SE) ml/min X 100 g, which was 56% of the left ventricular blood flow. The distribution of right atrial flow was not homogeneous. For example, flow to anterior right atriaater (105+/-8 ml/min X 100 g) than mean right atrial flow. Following ligation of the sinus node artery, perfusion of the segment containing the sinus node decreased by only 36%. Relative preservation of perfusion to the sinus node following sinus node artery ligation may explain why ligation of the sinus node artery does not alter heart rate. Furthermore, we also found that cannulation and pump perfusion of the sinus node artery at pressures 10 and 50 mm Hg greater than systolic pressure did not alter the distribution of right atrial flow. Thus, because cannulation and perfusion of the sinus node artery do not artifactually distort regional right atrial blood flow, we conclude that this should be a useful method for evaluating responsiveness of the sinus node to various interventions.
我们使用微球（7 - 10微米）对20只麻醉犬的右心房和窦房结区域的血流节段分布进行了评估。右心房平均血流量为83±7（标准误）毫升/分钟×100克，占左心室血流量的56%。右心房血流分布不均匀。例如，右心房前部的血流量（105±8毫升/分钟×100克）高于右心房平均血流量。在结扎窦房结动脉后，包含窦房结的节段灌注仅减少36%。窦房结动脉结扎后窦房结灌注相对保留可能解释了为什么结扎窦房结动脉不会改变心率。此外，我们还发现，在高于收缩压10和50毫米汞柱的压力下对窦房结动脉进行插管和泵灌注不会改变右心房血流分布。因此，由于对窦房结动脉进行插管和灌注不会人为地扭曲右心房局部血流，我们得出结论，这应该是一种评估窦房结对各种干预反应性的有用方法。
