顺行性/逆行同时灌注对缺血心肌灌注效果和能量代谢的影响  

Assessing the Effects of Simultaneous Antegrade/Retrograde Cardioplegia on Myocardial Perfusion and Energy Metabolism in Ischemic Myocardium

作　　者：李刚[1] 田伟忱[1] 景慎鸿[1] 李君权[1] 蒋树林[1] TIAN Gang-hong 

机构地区：[1]哈尔滨医科大学附属第二医院心脏外科,哈尔滨150086 [2]加拿大国家科学院生物诊断研究所

出　　处：《中国胸心血管外科临床杂志》2007年第1期31-35,共5页Chinese Journal of Clinical Thoracic and Cardiovascular Surgery

基　　金：黑龙江省自然科学基金资助项目(D200520)

摘　　要：目的应用磁共振成像(MRI)技术研究顺行性/逆行同时灌注(SARC)对缺血心肌的灌注效果和对能量代谢的影响。方法将18头家猪切取猪心后,经猪心左前降支(LAD)、主动脉、心前静脉升支和冠状静脉窦建立灌注通路,其中6只猪心用于评估心肌灌注效果,12只用于评估心肌能量代谢。应用MRI观察顺行性/逆行注入磁共振造影剂[钆喷替酸葡甲胺(Gd-DTPA)]后其在心肌的分布,磷31磁共振图谱(31P MRS)比较顺行性灌注(AC)和SARC期间缺血心肌的灌注效果和能量代谢。结果AC经主动脉注入Gd-DTPA,缺血心肌的MRI信号无变化,但是SARC无论经主动脉还是经冠状静脉窦注入Gd-DTPA,在缺血区域均可以见到Gd-DTPA的分布。31P MRS图谱显示:AC期间结扎LAD导致左室前壁心肌磷酸肌酸和三磷酸腺苷含量显著下降,而无机磷含量明显升高。但这些缺血反应可以被SARC灌注方法完全纠正。结论SARC同时灌注缺血心肌,其血流供应足以维持缺血心肌的正常能量代谢。Objective To assess the effects of simultaneous antegrade/retrograde cardioplegia （SARC） on myocardial perfusion and energy metabolism in ischemic myocardium using magnetic resonance imaging （MRI）. Methods After the hearts were harvested from 18 domestic pigs, left anterior descending artery, aorta, anterior ascending cardiac vein and coronary sinus were cannulated to establish the perfusion routes. 6 hearts were used to assess the effects of SARC on myocardial perfusion. Energy metabolism was observed in the other 12 pig hearts. MRI was used to monitor the distribution of contrast agent （gadolinium-diethylenetriamine penlaacetic acid, GdDTPA） in the myocardium after its injection through arterial and retrograde perfusion routes. The efficacies in sustaining myocardial perfusion and energy metabolism were evaluated by using phosphorus-31 magnetic resonance spectroscopy （sip MRS） during antegrade cardioplegia （AC） and SARC respectively. Results It was found that injection of Gd-DTPA into the aorta during AC did not result in signal increase in the ischemic myocardium on MRI. During SARC, however, Gd-DTPA was found in the ischemic region as well as in the other regions, no matter if it was given into the aorta or into the coronary sinus. Moreover,SiP spectra showed that occlusion of LAD during AC resulted in severe decrease of the levels of phosphocreatine （PCr） and adenosine triphosphate （ATP）, while the level of inorganic phosphate （Pi） increased in LAD-support myocardium. The abnormal metabolic changes were completely abolished by use of SARC. Conclusion It is concluded that SARC can deliver cardioplegic solution to the myocardium distal to a coronary occlusion and can sustain normal energy metabolism in the jeopardized myocardium.

关 键 词：顺行性/逆行同时灌注 磁共振成像 心肌保护 

分 类 号：R445.2[医药卫生—影像医学与核医学]