动物造模,动物实验 z-bio 2024-01-29 640

　　Transesophageal atrial pacing is a non-invasive, safe, and simple method for treating paroxysmal supraventricular tachycardia and atrial flutter, but it is ineffective for atrial fibrillation (Af). This article explores the feasibility and efficacy of transesophageal low-energy synchronous DC shock conversion to Af.

　　1. Experimental method: Seven healthy adult Guizhou miniature pigs, weighing 13.0 ± 3.14kg; Seven healthy adult hybrid dogs weighing 13.9 ± 5.4kg. Animals are free of gender. After fasting for 10 hours, intraperitoneal anesthesia was performed with pentobarbital sodium at a dose of 30-40mg/kg. Insert a specially designed gF six stage catheter into the esophagus through the mouth, connect the two distal electrodes to the LFYC-II arrhythmia treatment device, stimulate the atrium with a pacing frequency slightly faster than the animal's own rhythm, and continuously adjust the catheter position and pacing voltage. Find the catheter insertion depth that can capture the atrium 1:1 with the lowest pacing threshold, and then fix the catheter.

　　Use the modified XJJ-I cardiac emergency monitor for continuous electrocardiogram monitoring. Record and use it to provide complex electrical energy pulses. After modification, the machine can provide 20 levels of low-energy synchronous electrical energy pulses, including 0.25, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and 15J. Energy greater than 15J can be obtained while maintaining the original operating state of the machine.

　　Continuous intravenous infusion of 0.25-10000 units of acetylcholine is administered for several minutes, followed by stimulation of the atrium with high-frequency pulses of 800-1000 times/min through the esophageal electrode. Af is replicated, and its automatic rhythm time is observed and recorded. Af is then repeatedly induced, with the farthest electrode as the cathode and the second farthest electrode as the anode within a shorter interval than the automatic rhythm time. Starting from 1J of energy, it is sequentially increased by 1J for DC synchronous electric shock rhythm. The electric energy meter that can be converted to complex Af is called the complex law electric energy threshold. After the end of this experiment, each animal was subjected to several shocks unrelated to the conversion of Af through the same catheter, with a maximum single shock energy not exceeding 60J. Some animals take immediate esophageal specimens, while others are observed for 3 to 25 days before being euthanized. Esophageal specimens are taken and sent for continuous pathological sectioning and light microscopy observation.

　　2. Results: A total of 61 episodes of Af were induced in the entire group of animals, including 23 episodes of spontaneous conversion and 38 episodes of transesophageal low-energy synchronous electrical shock conversion. The electrical energy threshold for converting Af is 5.87 ± 2.02 (3-10) J. The duration of Af in the electroconverter was 3.02 ± 1.59 minutes, significantly shorter than that of 8.33 ± 8.48 minutes in the self reverter (t=4.240, P<0.0005)

　　Seven pigs were electrocuted to Af17 times, with a threshold of 6.33 ± 2.14J for repeated shocks; Seven dogs were electrocuted to Af21 times, with a threshold of 5.49 ± 1.93J for repeated shocks, and there was no significant difference between the two. According to body weight, animals weighing more than 12.5kg were electrocuted Af23 times, with a re shock energy threshold of 6.15 ± 2.39J; According to body weight, animals weighing less than 12.5kg underwent a total of 15 electric shocks to Af1, with a re shock energy threshold of 5.49 ± 1.93J, and there was no significant difference between the two.