心脏不停跳瓣膜置换手术对心肌线粒体通透性转换孔的影响

Effect and mechanism of on- pump beating- heart technique on the mitochondnal permeability transition pore

目的：探讨浅低温心脏不停跳手术对体外循环瓣膜置换患者心肌线粒体通透性转换孔（ mPTP）的影响。方法50例择期行人工机械瓣膜置换手术患者，随机分为心脏停跳组（停跳组）和浅低温心脏不停跳组（不停跳组），每组25例，停跳组在中度低温心脏停跳下完成心脏瓣膜置换手术，不停跳组在浅低温心脏跳动下完成手术。分别于体外循环转机前（T1）、转机30 min（T2）、停体外循环后4 h（T3）、72 h（T4）、120 h（T5）时取静脉血，测定血浆肌酸激酶同工酶（ CK-MB）及肌钙蛋白I （ cTnI）浓度；打开和关闭右心房时分别取右心房组织标本，检测心肌mPTP开放程度，并观察心肌超微结构。结果两组在T2～T4时点，CK-MB与cTnI浓度较T1时升高（P＜0.05），其中以停跳组明显（P＜0.05）；不停跳组mPTP开放程度较低、心肌线粒体超微结构变化较小。结论浅低温心脏不停跳手术在一定程度上可通过减轻手术中心肌mPTP的开放减轻心肌线粒体的损伤。

Objective To investigate the effect of on -pump beating-heart technique on myocardial mitochon-drial permeability transition pore （ mPTP） in patients with heart valve replacements undergoing cardiopulmonary bypass （CPB）.Methods Fifty patients undergoing elective artificial mechanical heart valve replacements with CPB were ran -domly divided into control group and beating group;in which conventional approach was used for 25 patients in the control group and on-pump beating-heart technique was performed in the beating group .Venous blood samples were collected before CPB （T1）, 30 min after CPB commencement （T2）, and 4 h （T3）, 72 h （T4）, and 120 h （T5） after weaning from CPB for the assessment of creatine kinase isoenzyme （CK-MB） and cardiac troponin I （cTnI）.Right atrial myocar-dial tissue samples were taken for assessment of mPTP and myocardial ultrastructure when the right atrium was opened and closed.Results In both groups , compared with the baseline values , plasma CK -MB and cTnI were significantly in-creased during CPB, while they were significantly more prominent in the beating group （P〈0.05）.Less mPTP opening and alteration in myocardial ultrastructure were observed in beating group than those in control group .Conclusion Beat-ing-heart technique may reduce myocardial mPTP opening , and mitigate the damage to myocardial mitochondria .