实时三维超声心动图观察兔室壁瘤形成过程的形态学特征

目的 应用实时三维超声心动图观察兔心肌梗死后不同时间段室壁瘤形成的形态学特征。方法 选取新西兰白兔20只,采用结扎左前降支中段及左旋支中段制作室壁瘤模型。普通饮食饲养4周后,将仍存活且有室壁瘤形成的实验动物纳入本研究,按照不同观察时间点分为术前、术后1天、2天、3天、1周、2周、3周、4周,并于术前及术后各时间点行二维超声心动图及实时三维超声心动图检查,并获取左心室射血分数、左心室舒张末期容积、左心室收缩末期容积、室壁瘤容积、左心室舒张末期内径、左心室短轴缩短率、左心室舒张末期左心室前壁厚度。结果 术后2天兔室壁瘤开始形成,术后3周基本形成,室壁瘤形成只数于术后2天至术后3周随时间呈增加趋势。与术前、术后1天比较,左心室收缩和舒张末期容积、左心室舒张末期内径及室壁瘤容积于术后2天至术后3周呈增加趋势(P<0.05),左心室前壁厚度、短轴缩短率及射血分数于术后2天至术后3周呈下降趋势(P<0.05),术后3周后趋于稳定。室壁瘤容积、室壁瘤容积占左心室舒张末期容积百分比与射血分数有较好的相关性(r=-0.778、-0.911,P均<0.001)。结论 室壁瘤容积与左心室舒张末期容积的百分比可作为评价兔心功能的重要参数。

Real-time three-dimensional echocardiography in assessment of morphologic characteristics of left ventricular aneurysm in rabbits

Objective To explore the morphologic changes of left ventricular aneurysm (LVA) by real-time three-dimensional echocardiography (RT-3DE) in rabbits. Methods Rabbit models of LVA were established in 20 New Zealand rabbits by ligating middle segment of left anterior descending artery and left circumflex artery. Four weeks later, the survived animals which had LVA formed were enrolled. RT-3DE and 2DE were performed preoperatively and 1 day, 2 days, 3 days, 1 week, 2 weeks, 3 weeks, 4 weeks after operation to obtain left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), as well as LVA volume, left ventricular internal dimension at end diastole (LVIDd), left ventricular fraction shortening (LVFS) and left ventricular anterior wall thickness at end diastole (LVAWd). Results LVA began from 2 days after operation and formed 3 weeks later. There was an increasing trend in the amount of LVA formation from 2 days to 3 weeks after operation. Compared with those preoperation and 1 day after operation, LVEDV, LVESV, LVIDd and LVA volume showed increasing trend (P<0.05), while LVFS, LVAWd and LVEF decreased (P<0.05) from 2 days to 3 weeks after operation, but did not fluctuate after 3 weeks. Moreover, there were correlations between LVEF and LVA volume, LVEF and LVA volume/LVEDV (r=-0.778, -0.911, both P<0.001). Conclusion The parameter of LVA volume/LVEDV can be as an important indictor for evaluating cardiac function of rabbit models.