左心室重建术对左心室重构的影响

Effect of Left Ventricle Reconstruction on Left Ventricular Remolding

目的探讨左心室重建术对左心室重构的影响.方法结扎14只普通级杂种犬冠状动脉,建立左心室室壁瘤模型,取犬正常心肌组织作为正常组;建模评估后将建模成功的犬平均分为2组,实验组犬通过左心室重建术(闭式折叠术)折叠室壁瘤、重建左心室,对照组犬则只进行开胸手术;6周后,采集对照组、实验组犬的非手术区心肌组织,使用实时荧光定量RT-PCR检测已采集的3个组的心肌组织AT1RmRNA、AT2RmRNA含量,并通过透射电镜观察各组心肌组织的超微结构.结果与正常组相比,实验组和对照组非手术区心肌组织中AT2R mRNA表达显著更高(P<0.05),AT1R mRNA的表达显著更低(P<0.05),AT2R mRNA/AT1R mRNA比值显著更高(P<0.05).相较于对照组,实验组非手术区心肌组织中AT2R mRNA的表达显著更低(P<0.05),AT1R mRNA的表达显著更高(P<0.05),AT2R mRNA/AT1R mRNA的比值显著更低(P<0.05);与正常组相比,实验组和对照组非手术区心肌组织电镜下都有心室重构(心肌间质内可见胶原蛋白沉着明显,胶原纤维明显增多)和心肌损害(心肌细胞内肌原纤维间隙增大,细胞质水肿,线粒体部分嵴断裂)的超微结构表现;与对照组相比,实验组的非手术区心肌组织电镜下心室重构和心肌损害程度小于对照组.结论左心室重建术在一定程度上可以延缓左心室重构的发生,降低心肌组织的损害程度,有助于预防心室重构的发生及改善心室重构的预后.

Objective To investigate the effect of left ventricular reconstruction on left ventricular remolding.Methods We selected twelve common dogs as experimental animals.We ligated the aeteria coronaria and established the model of ventricular aneurysm.We seleced the normal cardiac muscle as common group.After modelling and evaluating,the dogs of successful modelling were divided into two groups.The experimental group was rebuilt by the operation of left ventricular reconstruction（linear closure operation）.The control group was disclosed chest,yet it was not rebuilt by the operation of left ventricular（linear closure operation）;after six weeks of the operation of left ventricular reconstruction,we obtained the cardiac muscle of nonoperating field in every group.Then we detected the content of AT1R mRNA,AT2Rm RNA of the cardiac muscle of every group by RT-PCR and observed ultrastructure of the cardiac muscle of every group by electron microscope.Results Compared with normal group,the expression of AT2R mRNA was significantly higher（P〈0.05）,the expression of AT1R mRNA was significantly lower（P〈0.05）,and AT2R mRNA/AT1R mRNA ratio was significantly higher（P〈0.05） in experimental group and the control group.Compared with control group,the expression of AT2R mRNAwas significantly lower（P〈0.05）,the expression of AT1R mRNA was significantly higher（P〈0.05）,and AT2R mRNA/AT1R mRNA ratio was significantly lower（P〈0.05） in experimental group;Compared with the common group,ventricular remolding（collagen protein obviously deposited in the mesenchyme of cardiac muscle,collagen fibers became obviously larger） and cardiac damage（the gap of myofibrilla became larger in myocardial cell,cytoplasm dropsy,the part of mitochondria cristas was broken） ultramicrostructure took place in the cardiac muscle of the experimental group and the control group;compared with the control group,the extent of ventricular remolding and Cardiac damage of experimental group was less than the control group in the electron microscope.Conclusion Left ventricular reconstruction（linear closure operation） can delay the process of left ventricular remolding to a certain extent,lower the extent of cardiac damage and help to prevent the development of ventricular remolding and improve the prognosis of ventricular remolding.