de Jongh A L, Entcheva E G, Replogle J A, Booker R S, Kenknight B H, Claydon F J
Department of Biomedical Engineering, University of Memphis, Tennessee 38152-6582, USA.
Pacing Clin Electrophysiol. 1999 Jan;22(1 Pt 2):152-7. doi: 10.1111/j.1540-8159.1999.tb00323.x.
The objective of this study was to measure the defibrillation threshold (DFT) associated with different electrode placements using a three-dimensional anatomically realistic finite element model of the human thorax. Coil electrodes (Endotak DSP, model 125, Guidant/CPI) were placed in the RV apex along the lateral wall (RV), withdrawn 10 mm away from the RV apex along the lateral wall (RVprox), in the RV apex along the anterior septum (RVseptal), and in the SVC. An active pulse generator (can) was placed in the subcutaneous prepectoral space. Five electrode configurations were studied: RV-->SVC, RVprox-->SVC, RVSEPTAL-->SVC, RV-->Can, and RV-->SVC + Can. DFTs are defined as the energy required to produce a potential gradient of at least 5 V/cm in 95% of the ventricular myocardium. DFTs for RV-->SVC, RVprox-->SVC, RVseptal-->SVC, RV-->Can, and RV-->SVC + Can were 10, 16, 7, 9, and 6 J, respectively. The DFTs measured at each configuration fell within one standard deviation of the mean DFTs reported in clinical studies using the Endotak leads. The relative changes in DFT among electrode configurations also compared favorably. This computer model allows measurements of DFT or other defibrillation parameters with several different electrode configurations saving time and cost of clinical studies.
本研究的目的是使用人体胸部的三维解剖逼真有限元模型，测量与不同电极放置相关的除颤阈值（DFT）。将线圈电极（Endotak DSP，型号125，Guidant/CPI）沿侧壁置于右心室心尖（RV）、沿侧壁从右心室心尖撤回10 mm（RVprox）、沿前间隔置于右心室心尖（RVseptal）以及上腔静脉（SVC）。将有源脉冲发生器（罐体）置于皮下胸肌前间隙。研究了五种电极配置：RV→SVC、RVprox→SVC、RVSEPTAL→SVC、RV→罐体以及RV→SVC + 罐体。DFT定义为在95%的心室心肌中产生至少5 V/cm电位梯度所需的能量。RV→SVC、RVprox→SVC、RVseptal→SVC、RV→罐体以及RV→SVC + 罐体的DFT分别为10、16、7、9和6 J。在每种配置下测量的DFT均落在使用Endotak导线的临床研究报告的平均DFT的一个标准差范围内。电极配置之间DFT的相对变化也比较理想。该计算机模型允许使用几种不同的电极配置测量DFT或其他除颤参数，从而节省临床研究的时间和成本。
