风心病瓣膜置换术不同术式对心肌保护的比较研究

A comparative study on different surgical protocols of cardiac valve replacement for myocardial protection of patients with rheumatic heart disease.

目的 寻求更好的心肌保护方法和准确评价心肌保护的手段。方法 随机将 2 0例风心病二尖瓣置换者分为浅低温心脏跳动中 (不停跳 )组和中低温心脏停跳 (停跳 )组 ,各 10例。测定血浆和心肌组织中细胞因子降钙素基因相关肽 (CGRP)含量和心肌线粒体体视学定量分析。结果 1血浆 CGRP,两组内各时点与其术前比较 ,均有明显升高 (P<0 .0 1) ;在主动脉开放后 15 ,30 min、术后 2 h、6 h等 4个时点的含量 ,不停跳组均低于停跳组 (P<0 .0 5或 P<0 .0 1)。 2心肌CGRP,两组内各时点与其术前比较 ,含量均有明显下降 (P<0 .0 1) ;而术后含量不停跳组高于停跳组 (P<0 .0 5 )。 3心肌细胞线粒体体视学分析 :面数密度 (NA)和比表面 (δ)停跳组较不停跳组下降 ,而平均直径 (D)明显增大 (P<0 .0 5或 P<0 .0 1)。结论 研究提示浅低温心脏跳动中心内直视术对心肌损伤较轻 ,推测该术式并非主要是由于增加了保护性细胞因子的产生 ,从而减少了心肌缺血再灌注 (I/ R)

Objective To seek for optimal technique of myocardial protection by utilizing correct indexes evaluation.Methods Twenty patients who would undergo mitral valve replacement operation were randomly divided into tow groups:the beating heart group,comprising 10 cases for mild hypothermia and cardiopulmonary bypass(CPB);the arrested heart gramp,comprising 10 cases for mila hypothermio and cadiopulmonary bypass(CPB);the arrasted heart hraip,Compvising 10 cases for cold blood cardioplegia(CBC).Then the operations were performed and the pre ,intra and post operative samples of plasma and myocardium were measured by radiommunoassay.The ultrastructural indexes such as N A, and δ were analysed.Results ①The plasma levels of calcitonin gene related peptide(CGRP) were elevated significantly when compared with their basic levels before operation in the two groups( P <0.01).The levels of CGRP in the beating heart group were significantly lower than that of the arrested heart group at 15min and 30min after aortic de clamping,2h and 6h after operation( P <0.05, P <0.01).②In both groups,the CGRP content in myocardium was decreased significantly as compared with that before operation ( P <0.01),but the CGRP levels of the beating heart group were significantly higher than those of the arrested heart group after operation( P <0.05).③The stereological studies of myocardial mitochondria showed that the ultrastructural indexes N A and δ were significantly decreased,and was significantly increased in the arrested heart group( P <0.05, P <0.01).Conclusion The myocardial ischemic / reperfusion (I/R) injury in the beating heart group is less severe than that in the arrested heart group.It is inferred that the decreased myocardial I/R injury may not be mainly due to the increased protective factor.