心肌声学造影对心肌损伤影响因素的实验研究

The influence factors study of myocardial contrast echocardiography on myocardial injury

目的探讨不同剂量的国产左心声学造影剂“全氟显”在不同超声造影条件下（不同Ml或触发成像方式）心肌声学造影对大鼠心电及心肌组织损伤的影响。方法“全氟显”造影剂以125，250，625μl／kg三种剂量，0．56，0．99，1．80三种机械指数（MI）及两种触发方式（R波和T波触发），对三种变量进行3×3×2析因分析。90只SD大鼠，分成18个组，每组5只。各组在造影前经静脉注入伊文思蓝（EB，50mg／kg），随后注入微泡造影剂。观察指标为造影过程中室性早搏的发生数目、造影后心肌肌钙蛋白T（cTnT）的变化及心肌组织内EB含量。分别分析主效应及交互作用。结果根据析因分析结果，三种剂量间室性早博发生数比较差异无统计学意义（P〉0．05）；EB含量间比较（P=0．013），差异具有统计学意义，高剂量组EB含量高于低剂量组，其他两组比较，P〉0．05。三种MI之间室性早博发生数比较（P=0．029），高MI条件下产生室性早博的数目多于中MI，而其他两组间比较（P〉0．05）；EB含量亦有显著差异（P=0．006），高MI下EB含量显著高于其他两组，其他两组间P〉0．05。R波与T波触发发生室性早博的次数比较（P〉0．05），EB含量比较（P〈0．05），R波触发组高于T波组。室性早博数目三因素间无显著交互效应（P〉0．05）；EB含量三因素间有显著交互效应（P=0．000），EB含量最高发生于高剂量、高MI、R波触发组；各组cTnT均在正常范围。EB含量最高组大鼠心脏病理检查未见明显异常。结论在常规诊断超声条件下，注射高剂量造影剂在高MI及R波触发情况下毛细血管渗漏相对明显；高MI易致大鼠室性早博；各组cTnT含量在正常范围；心脏病理检查无明显异常。提示在本研究条件下，应用“全氟显”行动物心肌声学造影是安全的。

Objective To investigate the effects of MCE on electrocardiogram and myocardial injury by using ＂C3F8＂ contrast agent with different doses and different MI and trigger mode in rats. Methods Ninety SD rats were divided into 18 groups （ n = 5 ） randomly. Then the low （ 125 μl/kg） , middle （ 250 μl/kg） and high （ 625 μl/kg） doses of contrast media and low（0.56） , middle（0.99） and high（1.80） MI and R or T wave trigger mode were applied with 3× 3× 2 factorial analysis. Each group was injected with Evans blue （EB, 50 mg/kg） transvenous before contrast echocardiography, then microbubble contrast media was injected. The EB content, premature ventricular contraction （PVC）count and the change of troponinT（cTnT） content were observed. And the main effect and interaction effect were analyzed respectively. Results According to factorial analysis, there was no significant difference in PVC counts among three doses of contrast agent （ P 〉 0.05 ） , and there was significant difference in EB content among three doses of contrast agent （P = 0. 013 ）. EB content in high doses group was higher than that in low doses group （ P 〉 0.05 ）. There was significant difference in PVC counts and Evans blue content among three MI （ P = 0. 029 ）, PVC content in high MI group was more than that in middle MI group （ P 〉 0.05 ）, there was significant difference in EB content （P = 0. 006）. EB content in high MI group was obviously higher than that in other MI group （P 〉 0.05）. There was no significant difference between R and T wave trigger mode for PVC counts （ P 〉 0.05 ） , while there was significant difference in EB content （ P 〈 0.05 ）. There were no significant difference in PVC count among three factors （ P 〉 0.05 ）, while there were significant difference in EB content among three factors （ P = 0. 000）. The most EB content was in high dose, high MI and R wave group, eTnT in each group was normal. No obvious abnormality was found in rat heart pathologic examination in the most EB content group. Conclusion Under conventional uhrasonography, microvascular leak is obvious in high dose, high MI and R wave group, high MI can make rat get PVC easily, cTnT in each group is normal and no obvious abnormality could be found by heart pathologic examination. The results in this study indicated that the usage of C3F8 in MCE is safe.