动物造模,药效评价,心力衰竭 z-bio 2024-07-01 451

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

　　2. Method of modeling: Intravenous injection of ketamine 10mg/kg, atropine 0.5mg, and diazepam 1.0mg/kg. After successful anesthesia, lie on your back and establish a venous access. Open the brachiocephalic 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, fix it, connect the pacemaker to the electrode, and bury it subcutaneously in the scapular area of the pig. After surgery, use penicillin to resist infection for 1 week. After 1-2 days of recovery, start the pulse generator outside the body 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 after modeling, symptoms of decreased appetite and decreased exercise gradually appear; 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.

　　The echocardiography examination showed that the left atrial and ventricular diameters 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 the 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.