疾病动物模型,心房颤动 z-bio 2021-11-11 286

　　(1) Reproduction method Cats, dogs and rabbits are used as experimental animals. Cats and dogs are anesthetized with 3% sodium pentobarbital at a dose of 30 mg/kg body weight by intravenous or intraperitoneal injection, and rabbits are intravenously injected with 25% urethane 1g/kg. anesthesia. After anesthesia, the animal was fixed on its back, the mid-neck skin was incised, the trachea was intubated, the tracheal intubation was connected to an artificial ventilator for artificial respiration, the chest cavity was opened, and the normal lead II electrocardiogram was traced, and a small cotton ball impregnated with 5% acetylcholine was placed in the sinus. Observe the changes in the electrocardiogram in the atrial node area. After 1 min, use toothless forceps to gently pinch the atrium to cause atrial fibrillation. Record the electrocardiogram and observe the duration of the atrial fibrillation. Then pinch the atrium to cause atrial fibrillation and inject the study drug from the femoral vein 1 min later, and observe and record whether there is an antagonistic effect.

　　(2) Features of the model Local application of acetylcholine to induce atrial fibrillation has the characteristics of controllable location. And after removing the cotton ball, the trigger source can be quickly removed, and the animal's heart rhythm can be gradually restored, so it has the characteristics of controllable intensity. It is a commonly used animal model of atrial fibrillation.

　　(3) Comparative Medicine Atrial fibrillation (atrial fibrillation) is the most common arrhythmia in clinical practice, which often causes serious complications such as hemodynamic changes and cerebral thrombosis. The incidence rate is 2% to 4% for people over 60 years old, and 11% to 17% for people over 75 years old. Atrial fibrillation is common in patients with organic heart disease, and it is also seen in patients without organic heart disease (accounting for 3% to 11%). There is clinical evidence that shortened atrial refractory period (ERP) and multi-wave reentry play an important role in atrial fibrillation. The shortening of atrial ERP due to vagus nerve stimulation or application of acetylcholine can induce intra-atrial reentry and cause atrial fibrillation. This is because acetylcholine affects the normal conduction pathway due to local blockade of acetylcholine. In addition, the drug can shorten the atrial refractory period and reduce The effects of contraction strength and other effects lead to excitement as a result of circular motion. Atrial fibrillation caused by acetylcholine can be explained by a multiwavelet mechanism. The onset of atrial fibrillation requires simultaneous action of multiple wavelets in the room to maintain it.