开胸制备大鼠心肌梗死模型操作过程中同步肢胸导联心电图变化

摘要

目的：探讨开胸结扎大鼠左前降支过程中心电图的变化，以期为正确分析大鼠心肌梗死心电图提供依据。方法将大鼠分为非结扎组、结扎非关胸组及结扎关胸组，检测各时点心电图并进行比较。结果各组 QRS 起点偏移值差异无统计学意义（ P ﹥0.05）。三组大鼠的 J 点偏移值在 V5导联开胸后即减小（ P ﹤0.05）；两结扎组 J 点升高表现在Ⅰ、aVL、V5导联（ P ﹤0.05），两结扎组间差异无统计学意义（ P ﹥0.05）。T 波振幅在非结扎组及结扎非关胸组的 V2与 V5导联开胸后各时间点均低于开胸前（ P ﹤0.05）；在结扎关胸组的Ⅰ、aVL 导联关胸后增大，V5导联开胸后振幅减小，关胸后恢复，3个导联关胸后的振幅明显高于另外两组相应时点，上述差异均有统计学意义（ P ﹤0.05）。心电轴在结扎非关胸组于结扎后第二时点以及结扎关胸组自撕开心包后均较开胸前均减小（ P ﹤0.05）。结论开胸、撕开心包膜、关胸等操作可对大鼠心电图产生影响，在检测大鼠心肌梗死心电图时应予以考虑。%Objective To study of the ECG evolution during the process of ligating left anterior descending branch(LAD)by thoracotomy in rats. Methods Rats were divided into non - ligation group(NL group),LAD ligation without sternal closure group(LNSC group)and LAD ligation with sternal closure group(LSC group). ECG in each time point were recorded and analyzed. Results There was no statistical signifi-cance for the deviation value of QRS starting point in each group( P ﹥ 0. 05). After thoracotomy,all of the J point value in three groups were de-creased in lead V5( P ﹤ 0. 05). For the ligation groups,the J point elevated in leadⅠ,aVL and V5( P ﹤ 0. 05),and there is no statistical sig-nificance between the two ligation groups( P ﹥ 0. 05). After thoracotomy the T wave were lower than before in lead V2 and V5 in NL group and LNSC group( P ﹤ 0. 05). For the LSC group,T wave in leadⅠand aVL increase after sternal closure,and T wave amplitude in lead V5 de-creased after thoracotomy and recovered after sternal closure. In LNSC after sternal closure,T waves in leadⅠ,aVL and V5 were higher than the ones in the other two groups( P ﹤ 0. 05). The cardiac axis in LNSC group and the LSC group which was recorded in the second time point or after sternal closure were smaller than the ones recorded before thoracotomy( P ﹤ 0. 05). Conclusion Opening chest,tearing pericardium,closing chest may affect the electrocardiogram performance in rats. It should be taken into account in myocardial infarction rats when we analyze ECG.