高频右心房起搏建立犬心房颤动模型和植入式心电监测器的评估

Establishment of a canine atrial fibrillation model by high-frequency right atrial pacing and evaluation of an implantable electrocardiogram monitor

目的通过在传统常规高频心房起搏建模的方法中,创新性地运用精细的电极导线、先进的导管操控系统及植入式心电监测器追踪房颤发作情况,观察房颤模型建立的高效性及安全性。方法选取12只成年比格犬,随机分为空白对照组(6只),心房颤动模型组(AF组,6只)。AF组运用SelectSecure系统植入直径仅为4.1 Fr的细双极实心电极导线3830主动固定电极,连接专用房颤模型起搏器建立心房高频起搏系统,术后采用AOO起搏模式下的快速心房起搏的方法建立心房颤动模型,并运用植入式心电监测器Reveal LINQ追踪器实时追踪房颤的发生。采用心脏彩色超声显像仪,探头发射频率2.5 MHZ对实验犬进行超声心动图的检查,经心尖四腔测量左、右心房收缩末期心房面积。对左心房组织进行光镜及电镜形态学观察。结果12只实验犬中,AF组在建模过程中死亡2只,其余10只实验犬完成实验。成功建立房颤模型的时间为(10.63±2.13)周;房颤模型建立成功时,在AOO模式下,高频房颤模型起搏器心房刺激频率为(588.75±11.26)次/min。所运用的植入心电监测器可精确、高效地追踪记录AF组房颤负荷。房颤模型制作成功后,左心房面积较建模前显著增大[(8.20±0.83)cm^2与(3.80±0.08)cm^2相比,P<0.05];右心房面积较建模前增大[(4.52±0.44)cm^2与(2.75±0.96)cm^2相比,P<0.05];AF组左心房面积较对照组增大[(8.20±0.83)cm^2与(3.72±0.15)cm^2相比,P<0.05];右心房面积较对照组增大[(4.52±0.44)cm^2与(2.78±0.18)cm^2相比,P<0.05]。通过对心房颤动模型犬及空白对照实验犬进行左心房组织切片形态学观察提示心房颤动实验犬心房结构发生了重构。结论运用高频心房起搏可成功建立稳定的心房颤动模型。运用SelectSecure系统植入3830双极实心心房起搏电极,这一方法可精准植入电极并提高在实验犬中电极植入成功率。运用植入式心电监测器Reveal LINQ实时动态监测房颤负荷,可提高实验监测效率,高效、精确。

Objective In the traditional high-frequency atrial pacing modeling method,we innovatively used fine electrode wires,advanced catheter control system and implantable electrocardiogram(ECG)monitor to track atrial fibrillation,to observe the efficiency and safety of the atrial fibrillation model.Methods Twelve adult beagle dogs were randomly divided into control group(n=6)and atrial fibrillation model group(AF group,n=6).The SelectSecure system was used to implant a thin bipolar solid electrode wire 3830,the diameter of which is only 4.1 Fr,active fixed electrodes in the AF group,and connect the special atrial fibrillation model pacemaker to establish the atrial high-frequency pacing system.After the operation,rapid atrial pacing under the AOO pacing mode was used to establish the atrial fibrillation model,and the implantable ECG monitor,Reveal LINQ tracker,was used to track the occurrence of atrial fibrillation in real time.Color echocardiography was used to examine the echocardiogram of the experimental dogs with a probe emission frequency of 2.5 MHz.The end-systolic atrial area of the left and right atria was measured by echocardiography through the four apical chambers.The left atrium tissue was observed by light microscopy and electron microscopy.Results Two dogs died in the experiment and the other 10 dogs completed the experiment.The time it took to establish a successful atrial fibrillation was 10.63±2.13 weeks.After establishment of the atrial fibrillation model,the pacemaker atrial stimulation frequency for the high-frequency atrial fibrillation model was 588.75±11.26 beats/min under the AOO mode.The implantable ECG monitor used in this study was accurate and efficient,and can record the AF load dynamically.After the atrial fibrillation model establishment,the left and right atrial areas significantly increased(8.20±0.83 cm^2 vs.3.80±0.08 cm^2,P<0.05,and 4.52±0.44 cm^2 vs.2.75±0.96 cm^2,P<0.001,respectively).Furthermore,the left atrial area of the AF group was larger than that of the control group(8.20±0.83 cm^2 vs.3.72±0.15 cm^2,P<0.05)and the right atrium area was larger than before modeling(4.52±0.44 cm^2 vs.2.78±0.18 cm^2,P<0.05).Morphological observation of left atrial tissue sections from the atrial fibrillation model dogs and control dogs indicated that the atrial structure of the atrial fibrillation experimental dogs had been reconstructed.Conclusions A stable atrial fibrillation model was successfully established by high-frequency atrial pacing.The SelectSecure system was used to implant 3830 bipolar solid atrial pacemaker electrodes.This method accurately implants electrodes and improves the success rate of electrode implantation in experimental dogs.Real-time and dynamic monitoring of the atrial fibrillation load with an implantable ECG monitor,Reveal LINQ,improves the efficiency and accuracy of experimental monitoring.