心脏跳动中二尖瓣替换术对心肌保护的临床研究

目的 旨在为浅低温体外循环心脏不停跳心内直视手术对心肌保护效果作进一步客观的评价。方法 连续40例风湿性心脏病二尖瓣病变患者随机分为不停跳组（n=20）,停跳组（n=20）。两组均分别于体外循环前、后抽取静脉血测定血浆内皮素（ET）、心钠素（ANP）和切取右心房少许心肌组织作细胞超微结构进行对比分析。结果 停跳组ET、ANP波动范围大、变化剧烈,而不停跳组ET、ANP变化相对平缓、稳定,与停跳组相比差异显著（P〈0.05）;开放即刻至开放24 h停跳组ANP值高于不停跳组（P〈0.05）;在心肌超微结构方面,不停跳组基本无变化,停跳组各时点呈现损伤逐渐加重趋势。结论 浅低温体外循环心脏跳动中心内直视手术是一种较接近生理状态的心肌保护方法,能减轻心肌缺血缺氧损伤,避免再灌注损伤,保持心肌细胞形态结构的完整性,而获得较理想的心肌保护效果。

Research on the Myocardial Protection of Mitral Valve Replacement on Beating Heart

OBJECTIVE To make a further objective evaluation to the myocardial protective effect of beating heart with mild hypothermia and extracorporeal circulation(ECC) during open-heart operation.METHODS 40 patients with rheumatic heart disease were randomly allocated to two groups: beating heart group,20 cases of mitral valve replacement(MVR) on beating heart with mild hypothermia and ECC;arrested heart group,20 cases of MVR on arrested heart with ECC.The samples of plasma were obtained before and after ECC to survey the contents of endothelin(ET) and atrial natriuretic polypetide(ANP).The samples of myocardium were obtained during ECC through which myocardial ultra structure were observed and analyzed in two groups.RESULTS The range of ET and ANP fluctuated more dramatically and significantly in arrested heart group than in beating heart group.The contents of plasma ET in beating heart group were lower than in the arrested heart group from 15 minutes after arrested to 12 hours after aorta opened(P<0.05).The levels of ANP in beating heart group were higher than in arrested heart groups(P<0.05) during arrested time,and were lower than in arrested heart group from the beginning of open to the 24th hour after opening(P<0.05).CONCLUSION The open-heart surgery with beating heart is a good myocardial protective method closed to physiological condition,which may be attributed to the reduction of ischemic-reperfusion injury.The heart is better preserved in beating heart surgery,which has good myocardial protective effect.