Imaging-Assisted Interactive Ventricular Defibrillation

描述(由申请人提供)： 植入型心律转复除颤器(ICD)患者的生活质量受到除颤电击的影响。因此，为了减少疼痛和电池消耗，已经做出了重大努力来降低冲击能量。一项重大进展出现在80年代，当时发现双相电击在除颤方面比单相电击有效得多。随后在优化冲击波波形方面的努力只产生了微乎其微的改善，这表明需要在概念上取得突破，以推动更重大的进展。最近，由于1)在纤颤过程中实现波前组织，以及2)临床双室起搏/除颤设备的日益流行，允许在脑室放置额外的导线，因此在开发新的除颤方法方面出现了新的机会。这些新的进展暗示了通过实时检测波前组织和以空间分布的方式在周期到周期的基础上传递低能量脉冲来终止心律失常的潜在方法。这一竞争更新提出了一种新的方法，使用多电极、同步起搏技术来加强波前组织并终止纤颤，所需能量至少比强电击方法低两个数量级。将使用一个交互式的成像辅助起搏和除颤系统来检测和起搏可兴奋的间隙，以同步波前。波前组织将通过在纤颤过程中出现的位相奇异性来评估。具体目的是：1)研究波前同步中反馈起搏的机制；2)评价同步起搏终止纤颤的效果；3)设计结合同步起搏和高压电击的除颤新策略。目标1将为同步起搏中电极位置和间距的优化提供力学基础。在进行动物研究的同时，还将使用心脏比多胺进行广泛的数学建模，以确定最佳电极配置的理论。目标2将确定同步起搏作为终止纤颤的唯一手段的作用。目标3将测试三种新的除颤策略的有效性，除强烈电击外，还使用电击前或电击后同步起搏。在这些研究中，我们将使用离体兔心脏和离体猪右心室。该项目的成功实施将为心律失常的管理提供一种新的、低能量的电子起搏策略。

DESCRIPTION (provided by applicant): The quality of life in patients carrying implantable cardioverter-defibrillators (ICDs) is affected by the occurrence of defibrillation shocks. Consequently, significant efforts have been made to decrease the shock energy for less pain and battery drain. A major progress came in the 80s when biphasic shocks were found to be far more efficient than monophasic shocks in defibrillation. Subsequent efforts in optimizing shock waveforms have produced only marginal improvement, suggesting a conceptual breakthrough is required to prompt more significant advances. Recently, a new opportunity in developing novel defibrillation methods has emerged due to 1) the realization of wavefront organization during fibrillation, and 2) the growing popularity of clinical biventricular pacing/defibrillation devices that allow extra leads to be placed in the ventricles. These new developments hint the potential approach to terminate arrhythmias by detecting wavefront organization in real-time and delivering low-energy pulses on a cycle-to-cycle basis in a spatially distributed manner. This competing renewal proposes a novel approach that uses multi-electrode, synchronized pacing techniques to enforce wavefront organization and terminate fibrillation with an energy requirement at least two orders of magnitude lower than the strong shock approach. An interactive, imaging-assisted pacing and defibrillation system will be used to detect and pace in the excitable gaps to synchronize wavefronts. Wavefront organization will be evaluated by the occurrence of phase singularities dudng fibrillation. The specific aims are 1) To study the mechanisms of feedback pacing in wavefront synchronization; 2) To evaluate the efficacy of synchronized pacing in terminating fibrillation; 3) To design new defibrillation strategies combining synchronized pacing and high-voltage shocks. Aim 1 will provide mechanistic foundation for optimizing electrode location and spacing in synchronized pacing. Extensive mathematical modeling using cardiac bidomain will be performed in parallel to animal studies to theorize optimal electrode configurations. Aim 2 will establish the role of synchronized pacing as an exclusive means of terminating fibrillation. Aim 3 will test the efficacy of three new defibrillation strategies using pre-shock or post-shock synchronized pacing in addition to the strong shocks. We will use isolated rabbit heart and isolated swine right ventricle in these studies. Successful execution of this project will suggest a novel, low-energy electrical pacing strategy for the management of arrhythmias.