Imaging-Assisted Interactive Ventricular Defibrillation

描述（由申请人提供）： 植入式心律转复除颤器（ICD）患者的生活质量受到除颤电击发生的影响。因此，已经做出了重大努力来减少电击能量以减少疼痛和电池消耗。80年代取得了重大进展，当时发现双相电击在除颤中比单相电击有效得多。随后在优化冲击波形方面的努力只取得了微小的改进，这表明需要在概念上取得突破，以促进更重大的进展。最近，由于1）在纤颤期间实现波前组织，以及2）允许在心室中放置额外引线的临床双心室起搏/除颤设备的日益普及，出现了开发新型除颤方法的新机会。这些新的发展暗示了通过实时检测波前组织并以空间分布的方式在周期到周期的基础上提供低能量脉冲来终止心律失常的潜在方法。这种竞争性更新提出了一种新的方法，该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，其能量需求比强电击方法低至少两个数量级。将使用交互式成像辅助起搏和除颤系统来检测和起搏可兴奋间隙，以同步波前。波前组织将通过纤颤期间相位奇点的发生来评估。具体目的是：1）研究反馈起搏在波前同步中的作用机制; 2）评价同步起搏终止房颤的效果; 3）设计同步起搏与高压电击相结合的新除颤策略。目的1为优化同步起搏电极位置和间距提供了力学依据。将使用心脏双肌酶进行广泛的数学建模，同时进行动物研究，以理论化最佳电极配置。目标2将确立同步起搏作为终止纤颤的唯一手段的作用。目标3将测试除强电击外，使用电击前或电击后同步起搏的三种新除颤策略的有效性。我们将在这些研究中使用离体兔心脏和离体猪右心室。该项目的成功执行将为心律失常的管理提供一种新的低能量电起搏策略。

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.