动物造模,快速心房起搏房颤模型 z-bio 2021-12-22 448

　　[Modeling mechanism] The rapid atrial pacing atrial fibrillation model is currently the most studied and most widely used animal model of chronic atrial fibrillation. This mechanism is related to electrical and structural remodeling caused by rapid atrial pacing. Various animal models are displayed without exception. The reduction of effective atrial refractory period (ERP), the reduction of frequency adaptability, the obvious increase of atrial diameter and volume, and the increase of anisotropy promote multi-wave reentry. .. The main ionic mechanism is to down-regulate the L-type calcium current IC, L, the instantaneous outward potassium current Ito and the delayed rectifier potassium current IK.

　　[How to make a model]

　　(1) Dog: Use healthy adult male or female dogs weighing 16 to 30 kg. After intravenous anesthesia with pentobarbital sodium (30 mg/kg), use isoflurane (2 mg/kg) and intravenous chloralose (0.3-0.4 mg/kg) or acepromazine (0.3-0.4 mg/kg) ) Maintain general anesthesia. Through inhalation. 4% halothane to maintain general anesthesia, 2L/min nitrous oxide, 1L/min oxygen, 2L/min medical gas. Under the guidance of the X-ray equipment, the 6F quadrupole reed was sent from the femoral vein to the right atrium to determine the threshold of atrial pacing. Give the atrium 400 to 800 times/minute, which is 2 to 4 times the pulse width of 2 milliseconds, and the threshold voltage S1S1 (300 milliseconds) or S1S2 (S1S1/S1S2300ms/200 milliseconds, with a step reduction of 5 milliseconds). The programmed stimulation causes atrial fibrillation scan ).

　　(2) Goat: Use goats weighing 15-65 kg. Intravenous injection of thiopental sodium (10 mg/kg), inhalation of halothane (1% to 2%), 1:2 oxygen: nitrous oxide mixed gas to maintain general anesthesia. Open the left chest, cut the heart bag, place electrodes on the left and right non-atrial epithelial walls of goats and Bachmann bundles, suture the chest wall, and turn the electrodes into an external defibrillator, connect and stimulate multiple parts at the same time. The frequency of use is 50 Hz , The time is 1 millisecond, the interval is 20 milliseconds, and the intensity is a burst stimulus four times the extended phase threshold. Stimulation stops when electrical cardioversion occurs, and stops when electrical cardioversion occurs. If it changes to sinus rhythm, the stimulation continues.

　　(3) Other animals: This model can be successfully replicated in mice, rats, rabbits, etc. After anesthetizing the animal, place the electrode in the right atrium and perform radiofrequency stimulation. Most animals can induce atria. Fibrotic. Seizures. [Model Features] Acute radiofrequency stimulation can induce atrial fibrillation within 10 seconds to 30 minutes, while chronic radiofrequency stimulation lasting 6-8 weeks can reproduce spontaneous atrial fibrillation.

　　[Model Evaluation and Application] The animal model of atrial fibrillation established by rapid right atrial pacing has a high success rate, high reproducibility, and a long maintenance time of atrial fibrillation, leading to non-valvular diseases. , Myocardial remodeling, molecular biological changes and other clinical studies can also be used to study tachycardia cardiomyopathy and partial heart failure. However, this method requires attention to control the ventricular rate. This is because too fast ventricular rate can cause ventricular dysfunction, which leads to atrial changes that are not related to rapid atrial pacing.