Analysis of coronary slosh phenomenon under coronary stenosis by measurement of blood flow or vasucular diameter in intramyocardial vessels and microvessels

众所周知，心肌缺血经常在内膜下层观察到。虽然已经提出了几种可能的原因，与内膜下层和上膜下层之间的一些特征差异有关，例如收缩期的应力、血管外压、血管数密度和血细胞比容，但尚未给出结论性的原因。我们已经发现，在收缩期，由于心肌压缩，在舒张期流入内膜下心肌的部分血液被迫流入心外膜下动脉，这种反向的血流量是跨壁分布的重要决定因素。华盛顿大学的Feigl教授也预测了心脏收缩期血液从心内膜下向心内膜下转运的可能性。他将这种现象命名为“晃动”，并声称其具有病理生理学意义。本研究的目的是（1）检查血管舒张化合物和交感神经系统的作用， ...更多信息 EM对心脏收缩期心肌压缩引起的从心内膜下侧到心内膜下侧的血液运输（晃动）的影响，以及在冠状动脉狭窄的情况下这种影响的变化，以及（2）研究这些化合物是否可以允许均匀的血液分布（反晃动假设）。用20 MHz超声多普勒测速仪测量麻醉开胸犬隔动脉血流，并以前向流与后向流的比值来评价“晃动”程度。冠状动脉狭窄程度的增加以及冠状动脉内注射腺苷或硝酸甘油，都会增强“晃动”效应。结果表明，刺激α-交感神经系统可产生抗晃动效应，且抗晃动效应与心率呈线性关系。我们还用针探头CCD显微镜观察了内膜下心肌的冠状动脉微血管，发现在收缩期动脉直径减小约20%。动脉直径的这种减小被认为是引起“晃动”现象的原因。少

It is well known that myocardial ischemia is frequently observed in the subendocardial layer. Although several possible reasons have been claimed in relation to some characteristic differences between subendo- and subepi-cardial layers such as stress during systole, extravascular pressure, number density of blood vessels, and hematocrit, no conclusive reason is given yet. We have found that part of blood which flows into the subendocardial myocardium during diastole is forced to flow into the subepicardial artery by myocardial compression during systole and this reversed blood flow volume is an important determinant of transmural distribution. Prof. Feigl from University of Washington also predicted the possibility of blood transport from subendo- to subepi-cardial sides during systole. He then named this phenomenon "slosh" and has claimed its patho-physiological significance.The objectives of this study are (1) to examine the effect of vasodilating compounds and sympathetic nerve syst … More em on the blood transport (slosh) from subendo- to subepi-cardial sides by myocardial compression during systole and the change in this effect in the case of coronary artery stenosis and (2) to study if these compounds can allow uniform blood distribution (anti-slosh hypothesis). The blood flow in septal artery of anesthetized open-chest dog was measured using a 20 MHz ultrasound Doppler velocimeter, and the extent of "slosh" was evaluated as the ratio of forward to backward flows. The effect of "slosh" was augmented by an increase in coronary artery stenosis and by administrations of adenosine or nitroglycerin into a coronary artery. It was found that the stimulation of alpha-sympathetic nerve system led to an anti-slosh effect which was linearly associated with heart rate. We also observed coronary microvessels in the subendocardial myocardium using a needle-probe CCD microscope and found that the arterial diameter decreased about 20 % during systole. This decrease in arterial diameter is considered to cause the "slosh" phenomenon. Less