动物造模,心力衰竭模型 z-bio 2023-10-16 831

　　1. Animal modeling materials: Healthy Meishan pig, male, weighing 20-25kg; Medications: ketamine, atropine, diazepam, penicillin; Instruments: syringes, surgical instruments, YCP-D pacemakers, ventricular endocardium electrodes.

　　2. Method of modeling: Intravenous injection of ketamine 10mg/kg, atropine 0.5mg, and diazepam 1.0mg/kg. After successful anesthesia, establish a venous pathway in a supine position. Open the cephalic vein and insert the endocardial pacing electrode into the right ventricle under X-ray guidance. The pacemaker adopts YCP-D pacemaker, with a set pacemaker parameter threshold of<1V, voltage of 3.6V, and pulse width of 50ms. After meeting the conditions, the pacemaker is fixed, connected to the electrode, and buried subcutaneously in the scapular area of the pig. After surgery, penicillin is used to resist infection for 1 week. After 1-2 days of recovery, start the pulse generator in vitro and pace at a frequency of 230 beats per minute for 3 weeks.

　　3. Modeling principle: Rapid right ventricular pacing causes heart failure in animals.

　　4. After rapid pacing for 2 weeks, symptoms of decreased appetite and decreased exercise gradually appeared after modeling; By the end of the third week of pacing, all experimental pigs experienced shortness of breath, limb edema, and varying degrees of pleural effusion and galloping rhythm.

　　Echocardiography examination showed that the inner diameter of the left atrium and left ventricle increased to varying degrees compared to before pacing, the amplitude of ventricular wall activity was significantly reduced, the left ventricular ejection fraction was reduced, the left ventricular ejection time was shortened, and the isovolumic contraction time and isovolumic relaxation time were prolonged.

　　The Tei index, which reflects left ventricular systolic and diastolic function, significantly increases after pacing.

　　5. Precautions: Surgical instruments should be strictly disinfected to prevent surgical infections. Surgical trauma should be minimized and sterile operations should be strictly carried out.