NEURAL CONTROL OF THE CORONARY CIRCULATION IN HUMANS

交感神经和体液刺激影响冠状动脉 直接通过对冠状血管的影响产生血管阻力 间接通过对心肌的影响。 虽然 动物研究表明， 交感神经刺激通常使直接收缩肌黯然失色 最近的研究表明，直接影响可以发挥作用， 在控制冠状动脉血管阻力中起主导作用。 冠状动脉血管阻力的神经控制信息 人类是有限的，而且很难获得，主要是为了 方法上的原因。 我们最近开发了 确认了一种小型腔内多普勒导管， 测量清醒人类的相位冠状动脉血流速度。 我们将利用该导管研究冠状动脉血流速度 对反射和直接交感神经刺激的反应， 问题：1）神经源性收缩反应是否加重 在高胆固醇血症的存在下， 冠状动脉病变 2)这种反应是不是因为 冠状动脉粥样硬化 3)β受体阻滞剂能揭开 肾上腺素能冠状动脉血管收缩 冠状动脉病变 利用冠状动脉血流速度反应 冠状动脉内罂粟碱作为选择性血管扩张剂 储备和定量冠状动脉造影以评估病变 几何形状，我们将研究血管扩张储备，病变几何形状， 正常人冠状动脉血流速度的神经控制， 冠状动脉粥样硬化患者。 这种方法应 让我们对神经调节有了新的认识 冠状动脉循环中的一种。

Sympathetic neural and humoral stimuli influence coronary vascular resistance directly through effects on coronary vessels and indirectly through effects on the myocardium. Although animal studies suggest that the indirect dilator effects of sympathetic stimulation usually overshadow direct constrictor effects, recent work has shown that direct effects can play a dominant role in control of coronary vascular resistance. Information on neural control of coronary vascular resistance in humans is limited and has been difficult to obtain primarily for methodological reasons. We have recently developed and validated a small intralumenal Doppler catheter which can measure phasic coronary blood flow velocity in conscious humans. We will utilize this catheter to study coronary blood flow velocity in response to reflex and direct sympathetic stimuli asking three questions: 1) Is the neurogenic constrictor response accentuated in the presence of hypercholesterolemia without significant coronary lesions? 2) Is this response accentuated in the presence of coronary atherosclerosis? 3) Does beta blockade unmask accentuated adrenergic coronary vasoconstriction in patients with coronary lesions? Using the coronary blood flow velocity response to intracoronary papaverine as a measure of selective vasodilator reserve and quantitative coronary angiography to assess lesion geometry, we will study vasodilator reserve, lesion geometry, and neural control of coronary blood flow velocity in normals and patients with coronary atherosclerosis. This methodology should allow us to obtain fundamental new insights into neural regulation of the coronary circulation in humans.