Yang Fei, Patterson Robert
The Bakken Medical Instrumentation and Device Laboratory, Institute for Engineering in Medicine, University of Minnesota, 420 Delaware St., MMC 297, Minneapolis, MN 55455, USA.
Ann Biomed Eng. 2008 Oct;36(10):1659-67. doi: 10.1007/s10439-008-9548-2. Epub 2008 Aug 8.
The implantable cardioverter defibrillator with an active can and a single coil lead is effective in treating ventricular fibrillation, but the lead placement associated with the high defibrillation efficacy is still controversial and remains largely empirical. In this study, an anatomically realistic finite difference model of the thorax was developed based on MRI cross-sectional images of a human thorax to examine the effect of transvenous coil placement on defibrillation efficacy. Four electrode configurations with the coil was placed, respectively, in the right ventricular (RV) apex, in the middle of RV cavity, along the free wall in RV, or along the septal wall in RV, were simulated and their defibrillation efficacies were evaluated based on a set of metrics including voltage defibrillation threshold, current defibrillation threshold, interelectrode impedance, potential gradient distribution uniformity, current density distribution, and myocardium damage. It was found that the optimal electrode configuration is to position the coil in the middle of the RV cavity. The results were compared with the results from a simplified thoracic model. The comparison indicates that for a given electrode configuration a simplified representation of the thorax may overestimate defibrillation efficacy.
带有主动式罐体和单线圈导线的植入式心脏复律除颤器在治疗心室颤动方面是有效的，但与高除颤效果相关的导线放置仍存在争议，且在很大程度上仍是经验性的。在本研究中，基于人体胸部的MRI横截面图像开发了一个解剖学逼真的胸部有限差分模型，以研究经静脉线圈放置对除颤效果的影响。模拟了四种电极配置，线圈分别置于右心室（RV）心尖、RV腔中部、RV游离壁或RV间隔壁，并根据一组指标评估其除颤效果，这些指标包括电压除颤阈值、电流除颤阈值、电极间阻抗、电位梯度分布均匀性、电流密度分布和心肌损伤。结果发现，最佳电极配置是将线圈置于RV腔中部。将结果与简化胸部模型的结果进行了比较。比较表明，对于给定的电极配置，胸部的简化表示可能会高估除颤效果。
