| PrefaceCHD is one of heart diseases, which influence people's health seriously, so early diagnosis, evaluation of severity, and early treatment of CHD are very important. AMI is one of the most common causes of heart failure and death in human as emergency of CHD. Animal experiment plays an important role in evaluating of cardiac function of myocardial infarction. Rat can be used as an excellent animal model with the development of trans-gene technique because rat is cheap and easily obtained, and the gene of rat is similar with human. Researchers need a means to examine and evaluate quickly the cardiac structure and function of rat. Cardiac examination non-invasively plays an important role in vivo-evaluation of these small animals. High frequency echocardiography, MR1 and CT can be used to evaluate non-invasively left ventricular morphology, structure, and function of rat. MRI and CT, which are limited by high price and complicated operation, are not preferred. High frequency echocardiography can evaluate left ventricular morphology, structure, function, and flow of AMI rat. De Simome and Pfeffer began to evaluate cardiac structure and function of rat with echocardiography in 1990.But there is little research about which echocardiographic index can be used to evaluate the cardiac structure and function of rat. The change of cardiac structure and function of rat in different phases of AMI is seldom reported in literature. DTI pulse wave technique (DTI-PW) has been proved a good index to evaluate myocardial movement and left ventricular function in human. Whether DTI-PW can be used to evaluate segmental myocardial movement and function of rat is seldom reported. We explore by the control research between normal and AMI rat in different phases: How to evaluate AMI rat with echocardiographic index and the process of left ventricular remodeling of AMI rat in different phases; whether DTI-PW can be used to evaluate segmental myocardial movement and function of rat.ObjectiveTo explore the value of High frequency echocardiography and DTI-PW to evaluate cardiac structure and function and myocardial movement of Sprague-Dawley Rat models with AMI.MethodsProduction of Rat Models with Acute Myocardial InfarctionSprague-Dawley rats were anesthetized and intubated and ventilated with ventilator. Through a thoracotomy on the left side, Left anterior descending coronary artery was ligated proximally. Infarct area no less than 30% was large, and infarct area less than 30% was mild or moderate. Study Designs1. Evaluation of cardiac structure and function of AMI rat A) Comparison of AMI rats of different infarct areaCardiac structure and function of normal and AMI rats were examined with high frequency echocardiography in 2 weeks or 8 weeks after induction successfully. Normal and mild/moderate infarct and large infarct group rats were divided by infarct area, which was ascertained by Masson trichrome staining. The cardiac structure and function of three groups were compared. B Comparison of AMI rats of the large infarct area in different phasesCardiac structure and function of AMI rats were examined with high frequency echocardiography in 2 weeks and 8 weeks after induction successfully. Infarct area was ascertained by Masson trichrome staining. The cardiac structure and function in 2 weeks and 8 weeks of large infarct rats were compared.2. Comparison of myocardial movement and mitral valve orifice flow between normal and large infarct ratsThe left ventricular anterior and posterior wall myocardial movement of normal and AMI rats were examined with high frequency echocardiography and DTI in 8 weeks after induction successfully. Mitral valve orifice flow velocity was recorded by Doppler flow imaging. Infarct area was ascertained by Masson trichrome staining. Mitral orifice flowvelocity and myocardial movement were compared between the normal and the large infarct rats. 3. Reproducibility and variability analysisNormal rats were examined with high frequency echocardiography and DTI in...
|
PDF Full Text Request