Study on the effect of retrograde continuous warm blood cardioplegia

采用离体犬在体心脏模型，观察了逆行持续温血停搏液（RCWBCP）对急性冠状动脉闭塞再血管化术中心肌保护的作用。31只动物按停搏方式分为3组。第一组动物（n=10）通过主动脉根接受多剂量顺行输送的冷St.托马斯医院溶液。第二组动物（n=11）通过冠状窦逆行给予相同剂量的晶体溶液。第三组动物（n=10）经冠状窦接受RCWBCP。再灌注期间心率、主动脉流量和左心室最大dp/dt的恢复在能够支持再灌注后工作模式的动物（每组8颗心脏）之间相似。超声测微计测得的闭塞LAD分布区域的局部心肌功能在RCWBCP后再灌注期间没有显著改善，与这些功能数据相对应的，闭塞LAD分布区域的心肌pH在心脏停搏和再灌注期间没有被RCWBCP显著升高。尽管RCWBCP在心脏停搏期间将回旋动脉分布的心肌pH维持在显著高于其他两组心脏的水平，但它未能阻止右心室游离壁心肌pH的下降。这些结果表明，与通过顺行或逆行方式输送的低温晶体心脏停搏液相比，LAD闭塞60分钟后的RCWBCP可能不会提供显著的心肌保护益处。

The effects of retrograde continuous warm blood cardioplegia (RCWBCP) on myocardial preservation during surgical revascularization for acute coronary artery occlusion was investigated using isolated in-situ dog heart model subjected to occlusion of left anterior descending artery (LAD) for 60 minutes followed by 60 minutes of cardioplegic arrest and reperfusion after release of the coronary artery occlusion. Thirty one animals were devided into 3 groups according to the manner of cardioplegic arrest. The first group of animals (n=10) recieved multiple dose of cold St. Thomas Hospital solution delivered antegradely through the aortic root. The second group of animals (n=11) recieved the same dose of the crystalloid solution delivered retrogradely through the coronary sinus. The third group of animals (n=10) recieved RCWBCP through the coronary sinus. Recovery of heart rate, aortic flow and left ventricular maximum dp/dt during reperfusion was similar among the animals (8 hearts in each group) which were capable of supporting working mode after reperfusion. Regional myocardial function in the occluded LAD distribution measured by sonomicrometer was not significantly improved during reperfusion after RCWBCP.Corresponding to these functional data myocardial pH in the occluded LAD distribution was not significantly elevated by RCWBCP during cardioplegic arrest and reperfusion. Although RCWBCP maintained myocardial pH in the circumflex artery distribution at a significantly higher level during cardioplegic arrest compared to the other two groups of hearts, it failed to prevent a decline of myocardial pH in the right ventricular free wall. These results suggest that RCWBCP after 60 minutes of LAD occlusion may not provide a signicant benefit in myocardial preservation over hypothermic crystalloid cardioplegia delivered through either antegrade or retrograde manner.