Reduced Myocardial Reflow and Increased Coronary Vascular Resistance following Prolonged Myocardial Ischemia in the Dog
Reduced Myocardial Reflow and Increased Coronary Vascular Resistance following Prolonged Myocardial Ischemia in the Dog
复制标题
狗长期心肌缺血后心肌回流减少和冠状血管阻力增加
作者：
J. Willerson;J. Watson;I. Hutton;G. Templeton;D. Fixler
研究确定在不同时期的心肌缺血后，血液灌注的肝素化犬心脏是否发生冠状动脉血管阻力的改变和再流现象的减少。用放射性微球测定局部心肌血流量。用动脉周围血流传感器测量冠状动脉左前降支近端血流。心肌缺血120分钟后，左心室缺血部分的血流减少，左冠状动脉前降支阻力增加。血流减少是特定于缺血区域的心内膜下。生理盐水和硝酸异山梨酯（异索地尔）不能阻止冠状动脉血管阻力的增加，也不能显著减少缺血区域心内膜下部分的血流。高渗甘露醇使血清渗透压升高40 mmol /kg，可防止冠状动脉血管阻力的增加，改善缺血区心内膜下部分再流现象的减少。因此，心肌缺血120分钟后，犬心脏冠状动脉血管阻力增加，心内膜下缺血部分的血流显著减少。此外，高渗甘露醇可以预防冠状动脉血管阻力的增加，减少缺血区域心内膜下部分的血流。
Studies were performed to determine whether an alteration in coronary vascular resistance and a reduction in the reflow phenomenon occurred in the blood-perfused, heparinized canine heart after various periods of myocardial ischemia. Regional myocardial blood flow was measured with radioactive microspheres. Proximal left anterior descending coronary artery blood flow was measured with a periarterial flow transducer. Reduced reflow to the ischemic portion of the left ventricle and increased resistance in the left anterior descending coronary artery were present after 120 minutes of myocardial ischemia. The reduction in reflow was specific to the subendocardium of the ischemic area. Saline and isosorbide dinitrate (Isordil) did not prevent the increase in coronary vascular resistance or the significant reduction in reflow to the subendocardial portion of the ischemic area. Hypertonic mannitol given so as to increase serum osmolality 40 mosmoles/kg prevented the increase in coronary vascular resistance and modified the reduction in the reflow phenomenon to the subendocardial portion of the ischemic area. Thus, both an increase in coronary vascular resistance and a significant reduction in reflow to the subendocardial portion of the ischemic area occur in the canine heart after 120 minutes of myocardial ischemia. Moreover, the increase in coronary vascular resistance can be prevented and the reduction in reflow to the subendocardial portion of the ischemic area can be modified by the administration of hypertonic mannitol.