Sakamoto S, Yokoyama M, Akita H, Kawashima S, Okada T, Mizutani T, Fukuzaki H
Jpn Heart J. 1983 Jan;24(1):117-25. doi: 10.1536/ihj.24.117.
We developed a canine model with coronary stenosis produced by intraluminal obstruction with a micro-balloon occluder to assess the role of vasomotor tone of a large coronary artery with a preexisting fixed stenosis in the genesis of myocardial ischemia. Hemodynamic and electrocardiographic responses to ergonovine, an agent capable of provoking coronary spasm, were evaluated. In the absence of coronary stenosis, intracoronary infusion of 4 micrograms/min ergonovine had no systemic and coronary hemodynamic effects. Similarly, with various degrees of external obstruction created by a screw-type metal constrictor, ergonovine had little hemodynamic effects. By contrast, with a stenosis greater than 28.4 +/- 5.0 mmHg in pressure gradient, created by intraluminal obstruction which preserved active arterial vasomotion, ergonovine-induced vasoconstriction produced a marked decrease in coronary blood flow and distal coronary pressure, followed by ST-elevation. These deleterious effects of ergonovine on coronary hemodynamics were reversed completely by intracoronary infusion of nitroglycerin. Our results indicate that the effects of normal coronary arterial vasomotor activity on a stenosed vessel can cause myocardial ischemia.
我们构建了一种犬类模型，通过微球囊封堵器造成冠状动脉腔内阻塞以产生冠状动脉狭窄，来评估存在预先固定狭窄的大冠状动脉血管舒缩张力在心肌缺血发生过程中的作用。评估了对麦角新碱（一种能够引发冠状动脉痉挛的药物）的血流动力学和心电图反应。在无冠状动脉狭窄的情况下，冠状动脉内输注4微克/分钟的麦角新碱对全身和冠状动脉血流动力学无影响。同样，使用螺旋式金属收缩器造成不同程度的外部阻塞时，麦角新碱对血流动力学影响很小。相比之下，当通过腔内阻塞造成压力梯度大于28.4±5.0 mmHg的狭窄且保留动脉主动血管运动时，麦角新碱诱导的血管收缩会导致冠状动脉血流和冠状动脉远端压力显著降低，随后出现ST段抬高。冠状动脉内输注硝酸甘油可完全逆转麦角新碱对冠状动脉血流动力学的这些有害影响。我们的结果表明，正常冠状动脉血管舒缩活动对狭窄血管的影响可导致心肌缺血。
