动物造模,动物实验 z-bio 2023-10-11 821

　　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 both male and female. After fasting for 10 hours, intraperitoneal anesthesia was performed with pentobarbital sodium 30-40mg/kg. Insert a specially designed gF six stage catheter into the esophagus through the mouth, connect the distal two electrodes to the LFYC-II arrhythmia treatment instrument, 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, this machine can provide a total of 20 levels of low energy synchronous electric 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. Electric energy greater than 15J can be obtained while maintaining the original working state of the machine.

　　Continuous intravenous infusion of 25000 to 10000 units of acetylcholine was used. After a few minutes, the esophagus electrode was used to stimulate the atrium with 800-1000 high-frequency pulses per minute. Af was replicated, and its automatic cardioversion time was observed and recorded. Af was then repeatedly induced. Within a shorter interval than the automatic cardioversion time, the farthest electrode was used as the cathode, and the second farthest electrode was used as the anode. Starting from 1J energy, it was sequentially increased by 1J for DC synchronous electric cardioversion. The electric energy meter that can convert to complex Af is 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 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 shock conversion. The electrical energy threshold of Af conversion is 5.87 ± 2.02 (3-10) J. The duration of Af in electroconverters was 3.02 ± 1.59 minutes, which was significantly shorter than the 8.33 ± 8.48 minutes of those who underwent self conversion (t=4.240, P<0.0005)

　　A total of 7 pigs were electrocuted to Af17 times, with a re shock energy threshold of 6.33 ± 2.14J; Seven dogs were electrocuted to Af21 times, with a re shock energy threshold of 5.49 ± 1.93J, and there was no significant difference between the two. According to body weight, animals with a weight greater than 12.5kg were electrocuted Af23 times, with a re shock energy threshold of 6.15 ± 2.39J; According to body weight, animals 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.