动物造模,心律失常 z-bio 2021-11-23 449

　　(1) Replication method Male rats weighing 250-450g are anesthetized by intraperitoneal injection of 3% sodium pentobarbital (40mg/kg), fixed in the supine position, separated from the carotid artery to record blood pressure, and the skin is cut in the middle of the neck. Separate the tracheal intubation and connect it to an artificial respirator for artificial respiration, with a respiratory frequency of 54 times/min, and a ventilation volume of 20ml/kg each time. Separate one side of the femoral vein for medicinal use. Needle-shaped electrodes are pierced into the rat limbs subcutaneously to connect an electrocardiograph and an electrocardioscope for continuous observation and recording of lead II electrocardiogram. Cut the chest wall at the 4th and 5th intercostal space on the left side of the sternum to expose the heart. After cutting the heart capsule, gently press the chest wall to squeeze out the heart. Use a small curved needle to thread a silk thread under the left anterior descending branch of the coronary artery to tie a virtual knot. Put the heart into the thoracic cavity. After the above-mentioned surgical treatment, the animal may experience arrhythmia and blood pressure drop. After 15 minutes of stability, the coronary arteries can be ligated. After the coronary artery is ligated, the blood pressure can drop significantly, but the heart rate does not change much. Approximately 5 minutes after the ligation, the animal showed obvious ventricular ectopic heart rhythm. Ventricular ectopic heart rhythm is most obvious within 30 minutes after ligation, and it reaches a peak around 10 minutes. Further, there may be deep Q waves, a significant increase in ST segment, and a prolonged QT interval. Most animals usually recover stable sinus rhythm after 30 minutes of ligation, and a few animals can last for 1.5 to 4 hours.

　　(2) Model features This model can observe the number of ventricular ectopic rhythms, paroxysmal ventricular tachycardia and the duration of ventricular fibrillation (s) within 30 minutes after coronary artery ligation in the model animal, which can be used to evaluate drugs effect. The model animals are small in size, have a wide range of sources, and the surgical operation is simpler than that of ligating the canine coronary artery. The model has a higher success rate, so it can be used as an effective method for screening antiarrhythmic drugs.

　　(3) Comparative medicine. Anesthetized rats with coronary artery ligation-induced arrhythmia model can still observe the effect of drugs on the area of myocardial infarction after coronary artery ligation. The disadvantage is that the anterior descending branch of the coronary artery varies greatly in rats, and the ligation site is difficult to be in the same position every time. The ligation speed can also affect the severity of arrhythmia.