冷停跳液右房逆行灌注对有冠状动脉梗阻的缺血心肌保护

Myocardial protection by retrograde cold cardioplegic solution through right atrium in the presence of coronary artery obstruction

观察了冷停搏液逆行灌注(RP)在有冠状动脉梗阻时对1小时缺血心肌的保护作用。12只实验犬分成主动脉根部灌注(AP)和(RP)两组。与AP组相比,RP组对梗组的左前降支辖区心肌降温低,复灌后氧耗少和心功能恢复好。RP组心缺血后心电图和心肌超微结构均正常,而AP组S-T段明显抬高,心肌纤维水肿、线粒体肿胀。由此表明,RP在有左前降支梗阻时,便利冷停搏液在心肌内均匀分布,增加缺血心肌保护效果,而AP保护心肌较差。

This experiment was done to compare the effects of antegrade and retrograde cold cardioplegic solutions on myoeardium in the presence of coronary obstruction. Twelve mongrel dogs were anesthetized with intravenous pentobarbital, and immediately after the left anterior descending of coronary artery (LAD) was tied off, all subjects were randomly allocated to receiving antegrade cardioplegic solution (4 C) through arotic root at initial dose of 20ml·kg^(-1) and supplemental dose of 10ml·kg^(-1) with perfusion pressure being 10.7kPa every 20 minutes (group n=6), or antegrade cardioplegic solution in the same way as mentioned above at initial dose of 10ml·kg^(-1) and retrograde cardioplegic solution at initial dose 10ml·kg^(-1) and supplemental dose of 10ml·kg^(-1) with perfusion pressure being 5.3kPa every 20 minutes (group Ⅱ, n=6), respectively. The occlusion of LAD lasted 60 minutes. As compared with the values of group Ⅰ, in group Ⅱ, there was a lower hypothermia in the myocardial re gion supplied by LAD during ischemia (P<0.05); myocardial oxygen consumption decreased significantly and cardiac function recovered better after the separation of CPB (P<0.05). Electrocardiogram and myocardial uhrastructure kept normal in group Ⅱ, however, there were significant elevations of S-T segments, Swelled myocardial fibers and mitochondria in group Ⅰ. It is suggested that retrograde perfusion through right atrium may more effectively improve the distribution of cold cardioplegic solution in the myocardium and the myocardial protection in the presence of coronary artery obstruction.