【Animal Modeling】-High-frequency right atrial pacing to establish a canine atrial fibrillation model and evaluation of implantable ECG monitors

  Objective: In the traditional conventional high-frequency atrial pacing modeling method, innovatively use fine electrode leads, advanced catheter control system and implantable ECG monitor to track the onset of atrial fibrillation, and observe the establishment of atrial fibrillation model. efficiency and safety.

  Methods: Twelve adult beagle dogs were selected and randomly divided into blank control group (6 dogs) and atrial fibrillation model group (AF group, 6 dogs). The AF group was implanted with a thin bipolar solid with a diameter of only 4.1 Fr using the SelectSecure system. Electrode lead 3830 was actively fixed with electrodes, connected to a special atrial fibrillation model pacemaker to establish a high-frequency atrial pacing system, and the atrial fibrillation model was established by the method of rapid atrial pacing in the AOO pacing mode after operation, and implanted ECG was used to establish the atrial fibrillation model. The monitor RevealLINQ tracker was used to track the occurrence of atrial fibrillation in real time. Echocardiography was performed on experimental dogs using a cardiac color ultrasound imaging device with a probe transmission frequency of 2.5MHZ, and the left and right atrial areas at end-systole were measured through the apical four-chamber. The left atrial tissue was observed by light microscopy and electron microscopy.

  Results: Among the 12 experimental dogs, 2 died during the modeling process in the AF group, and the remaining 10 experimental dogs completed the experiment. The time to successfully establish the atrial fibrillation model was (10.63±2.13) weeks; when the atrial fibrillation model was successfully established, the In AOO mode, the atrial stimulation frequency of the pacemaker in the high-frequency atrial fibrillation model is (588.75±11.26) times/min. The implanted ECG monitor used can accurately and efficiently track and record the load of atrial fibrillation in the AF group. Atrial fibrillation model After successful fabrication, the area of the left atrium was significantly larger than that before modeling [(8.20±0.83) cm2 compared with (3.80±0.08) cm2, P<0.05]; the area of the right atrium was larger than that before modeling [(4.52±0.44 ) cm2 compared with (2.75±0.96) cm2, P<0.05]; the left atrial area in the AF group was larger than that in the control group [(8.20±0.83) cm2 compared with (3.72±0.15) cm2, P<0.05]; right The atrial area was larger than that of the control group [(4.52±0.44) cm2 compared with (2.78±0.18) cm2, P<0.05]. The morphological observation of left atrial tissue sections in atrial fibrillation model dogs and blank control experimental dogs indicated that the atrium was Atrial remodeling in experimental dogs with fibrillation.

  Conclusion: A stable model of atrial fibrillation can be successfully established by using high-frequency atrial pacing. Using the SelectSecure system to implant 3830 bipolar solid atrial pacing electrodes, this method can accurately implant electrodes and improve the success rate of electrode implantation in experimental dogs . Using the implantable ECG monitor RevealLINQ to dynamically monitor atrial fibrillation load in real time can improve the experimental monitoring efficiency, efficiency and accuracy.