Objective To investigate the onset of left ventricular remodeling (LVRM) after acute myocardium infarction (AMI) and its changes within 6 hours in dogs on echocardiography. Methods AMI was induced in 14 dogs by ligating the left anterior descending arteries. Eight myocardium infarcted models were successful and were sacrified for pathological study. The indices of LVRM: wall infarction thickness (WIT), the wall motion score index (WMSI), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV) and left ventricular ejection fraction (LVEF) were evaluated before and 1 h, 2 h, 3 h, 4 h, 5 h and 6 h after operation. Results Compared with the pre-operation, WIT and LVEF were decreased (P<0.01), LVESV and WMSI were increased (P<0.01), and LVEDV was increased (P<0.05 or P<0.01) at every time point after operation. WIT had no significant difference at 1 h, 2 h, 3 h, 4 h, 5h and 6h after operation (P＞0.05). LVEDV, LVESV were higher (P<0.05) and LVEF was lower (P<0.05 or P<0.01) at 4 h, 5 h, and 6 h than at 1 h, and 2 h after operation. WMSI was higher at 3 h, 4 h, 5 h, and 6 h than at 1h (P<0.05). Conclusions In our experiment, LVRM occurred at 1 h after AMI in dogs. Thus echocardiography may evaluate early LVRM.%目的 采用超声心动图检测犬急性心肌梗死(AMI)后左心室重构发生时间及6 h内左心室重构变化.方法 对14只健康成年犬麻醉后开胸结扎左冠状动脉左前降支制备AMI模型,成功制备8只AMI模型,超声心动图分别于术前,术后1、2、3、4、5及6 h观察梗死心肌室壁厚度(WIT)、室壁运动积分指数(WMSI)、左心室舒张末期容积(LVEDV)、左心室收缩末期容积(LVESV)、左心室射血分数(LVEF).检查结束后处死实验犬,取梗死区心肌组织行病理学检查.结果 与术前比较,术后1 h实验犬WMSI、LVESV(P<0.01)和LVEDV(P<0.05)增大,LVEF和WIT减小(P<0.01);WMSI术后3、4、5、6 h高于术后1 h(P<0.05);术后4、5、6 h和术后2 h比较,LVEDV和LVESV增高,LVEF降低.病理检查显示:梗死区心肌细胞发生肿胀,肌浆呈颗粒状凝集而分布不均,出现核固缩.结论 犬AMI后1 h即可出现左心室重构,超声心动图可评估AMI后早期左心室重构.
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