Canty J M, Klocke F J
Department of Medicine, State University of New York at Buffalo 14215.
Circ Res. 1987 Nov;61(5 Pt 2):II107-16.
We have examined the temporal response of regional subendocardial function in conscious chronically instrumented dogs following implantation of a circumflex ameroid occluder. Collateralization was limited by ligation of epicardial anastamoses between the circumflex and adjacent coronary arteries at the time of instrumentation. Sonomicrometrically measured regional function in the circumflex coronary artery became depressed relative to that in the left anterior descending coronary artery bed under resting conditions with the onset of an aortic-circumflex pressure gradient of 15 +/- 2.9 mm Hg (mean +/- SEM). At the time of total ameroid occlusion, the ratio of circumflex to left anterior descending coronary artery function fell to 68 +/- 8% of control, with mean circumflex coronary pressure decreasing to 60 +/- 1.6 mm Hg. Following ameroid occlusion, distal coronary pressure increased, and circumflex function recovered towards control but remained depressed relative to that in the left anterior descending coronary artery for 2-4 weeks. Measurements of regional subendocardial perfusion suggested a dissociation between subendocardial flow and function prior to but not following coronary occlusion by the ameroid. We conclude that this model results in reductions in regional function that are relatively prolonged and are not readily attributable to subendocardial infarction or a critical reduction in resting coronary flow. The data suggest that functional adaptations in response to gradually developing coronary occlusion are more complex than those associated with acute reductions in coronary artery pressure and flow.
我们研究了在植入左旋支类淀粉样蛋白封堵器后，清醒且长期植入仪器的犬类区域心内膜下功能的时间反应。在植入仪器时，通过结扎左旋支与相邻冠状动脉之间的心外膜吻合支来限制侧支循环形成。在静息状态下，当主动脉 - 左旋支压力梯度达到15±2.9毫米汞柱（平均值±标准误）时，超声心动图测量的左旋支冠状动脉区域功能相对于左前降支冠状动脉床的功能开始下降。在类淀粉样蛋白完全封堵时，左旋支与左前降支冠状动脉功能的比值降至对照组的68±8%，左旋支冠状动脉平均压力降至60±1.6毫米汞柱。类淀粉样蛋白封堵后，远端冠状动脉压力升高，左旋支功能恢复至接近对照组，但相对于左前降支冠状动脉仍在2 - 4周内处于降低状态。区域心内膜下灌注测量表明，在类淀粉样蛋白冠状动脉封堵之前但不是之后，心内膜下血流与功能之间存在分离。我们得出结论，该模型导致区域功能降低，且这种降低相对持久，并非易于归因于心内膜下梗死或静息冠状动脉血流的严重减少。数据表明，对逐渐发展的冠状动脉封堵的功能适应比与冠状动脉压力和血流急性减少相关的适应更为复杂。
