Aguel F, Eason J C, Trayanova N A, Siekas G, Fishler M G
Tulane University, Department of Biomedical Engineering, New Orleans, Louisiana 70118, USA.
Pacing Clin Electrophysiol. 1999 Jan;22(1 Pt 2):158-64. doi: 10.1111/j.1540-8159.1999.tb00324.x.
Optimizing lead placement in transvenous defibrillation remains central to the clinical aspects of the defibrillation procedure. Studies involving superior vena cava (SVC) return electrodes have found that left ventricular (LV) leads or septal positioning of the right ventricular (RV) lead minimizes the voltage defibrillation threshold (VDFT) in endocardial lead-->SVC defibrillation systems. However, similar studies have not been conducted for active-can configurations. The goal of this study was to determine the optimal lead position to minimize the VDFT for systems incorporating an active can. This study used a high resolution finite element model of a human torso that includes the fiber architecture of the ventricular myocardium to find the role of lead positioning in a transvenous LEAD-->can defibrillation electrode system. It was found that, among single lead systems, posterior positioning of leads in the right ventricle lowers VDFTs appreciably. Furthermore, a septal location of leads resulted in lower VDFTs than free-wall positioning. Increasing the number of leads, and thus the effective lead surface area in the right ventricle also resulted in lower VDFTs. However, the lead configuration that resulted in the lowest VDFTs is a combination of mid-cavity right ventricle lead and a mid-cavity left ventricle lead. The addition of a left ventricular lead resulted in a reduction in the size of the low gradient regions and a change of its location from the left ventricular free wall to the septal wall.
优化经静脉除颤电极的放置仍然是除颤程序临床方面的核心问题。涉及上腔静脉（SVC）返回电极的研究发现，在经心内膜电极-SVC除颤系统中，左心室（LV）电极或右心室（RV）电极的间隔定位可使除颤阈值电压（VDFT）最小化。然而，尚未对有源罐配置进行类似的研究。本研究的目的是确定在包含有源罐的系统中使VDFT最小化的最佳电极位置。本研究使用了一个包含心室心肌纤维结构的人体躯干高分辨率有限元模型，以研究经静脉电极-罐除颤电极系统中电极定位的作用。研究发现，在单电极系统中，右心室电极的后部定位可显著降低VDFT。此外，电极的间隔位置比游离壁位置导致更低的VDFT。增加电极数量，从而增加右心室中的有效电极表面积，也会导致更低的VDFT。然而，导致最低VDFT的电极配置是右心室中腔电极和左心室中腔电极的组合。添加左心室电极导致低梯度区域的大小减小，并且其位置从左心室游离壁改变到间隔壁。
