目的 探讨长耳白兔术后心脏与周围组织粘连程度对心功能的影响及MRI表现.方法 对30只日本长耳白兔经开胸并在冠状动脉左旋支距心尖部1.0 cm处结扎建立心肌梗死模型.术后1 h内因心室性颤动死亡3只,术后严重感染2只.共25只长耳白兔成功建立心肌梗死模型.术后第8周对25只长耳白兔行心功能的MRI检查,测定各项左室心功能参数,包括:舒张末期容积(end diastolic volume,EDV)、收缩末期容积(end systolic volume,ESV)、每博输出量(stroke volume,SV)、射血分数(ejection fraction,EF),以及观察左室心功能参数随粘连程度变化的MRI表现.结果 25只长耳白兔中,无粘连(无粘连组)7只,轻度粘连(轻度粘连组)5只,中度粘连(中度粘连组)6只,重度粘连(重度粘连组)7只.EDV值在无粘连组、轻度粘连组、中度粘连组、重度粘连组组间比较差异均无统计学意义(均P＞0.05).ESV值在无粘连组、轻度粘连组、中度粘连组组间比较差异均无统计学意义(均P＞0.05),无粘连组、轻度粘连组、中度粘连组ESV、SV、EF值与重度粘连组比较差异均有统计学意义(P＜0.05或P＜0.01).无粘连组、轻度粘连组SV、EF值与中度粘连组比较差异均有统计学意义(均P＜0.05).线性相关性分析结果示:SV、EF与粘连程度之间均具有线性关系(r2=0.585、0.799,均P＜0.01).粘连后的MRI表现为:室壁运动不均衡,收缩时左室前壁可见有小尖角状变形或与胸壁间可见宽接触面,边缘成角.结论 在兔心肌梗死模型建立过程中,心脏术后重度粘连会明显影响心功能,尤其以收缩功能最为明显,这种模型在研究中应予剔除.%Objective To explore the effect of postoperative pericardial adhesions on cardiac function and MRI performance in rabbits. Methods Thirty Japanese long-eared white rabbits underwent thoracotomy and ligation of left circumflex coronary artery 1.0 cm from the apex to produce myocardial infarction. Three rabbits died due to ventricular fibrillation within 1 hour after operation and 2 had serious infections. Myocardial infarction was successfully induced in 25 rabbits. At 8 weeks after operation, cardiac MRI examination was performed and end-diastolic volume (EDV), end systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) were messured. Results Among the 25 rabbits,no adhesions were observed in 7 (no adhesions group) ,mild adhesions in 5(mild adhesions group) , moderate adhesions in 6 (moderate adhesions group) and severe adhesions in 7(severe adhesions group). NO differences in EDV were found among the four groups and in ESV among no adhesions group, mild adhesions group and moderate adhesions group (all P＞0.05). ESV,SV and EF in severe adhesions group significantly differed from the other three groups,and SV and EF in moderate adhesions group obviously differed from no adhesions group and mild adhesions group (P＜0.05 or P＜0.01). SV and EF were linearly related to the degree of adhesions(r2 =0. 585,0. 799, respectively; P＜0.01). MRI of adhesions showed disproportionate wall motion, a small cusp-like anomaly of left ventricular anterior wall during the systolic phase,and wide contact between ventricle and chest wall with angled edge. Conclusion In the preparation of myocardial infarction model,severe postoperative pericardial adhesions can exert significant affect on cardiac function,particularly on systolic function. Such models should be excluded in studies of cardiac function.
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