3D Ultrasound Current Source Density Imaging for Treatment of Heart Arrhythmia

描述（由申请人提供）：复发性心律失常是一种严重的健康问题，影响了400多万美国人，占与心脏病相关的所有死亡人数的20%。在药物治疗无效的晚期病例中，心律失常通常采用再同步或消融治疗。纠正耐药心律失常的心内消融术依赖于心脏激活波的精确图谱。尽管介入心脏手术治疗心律失常在全球范围内取得了成功，但心脏电生理（EP）制图仍有明显的局限性；例如，复杂且昂贵的程序容易产生图像配准错误，对识别短暂性心律失常无效，并且空间分辨率相对较差（5-10 mm）。为了克服一些限制并显著改进心电成像程序，我们提出了一种实时成像心脏电流和生物电位的新方法。因此，该项目将发展超声电流源密度成像（UCSDI），以极大地增强和促进心脏的心电成像。UCSDI是基于局部压力和电阻率之间的声电（AE）相互作用来远程检测组织中的电流。正如我们在各种制备中所展示的那样，超声波通过组织会产生接近超声频率并与局部电流密度成正比的电压调制（AE信号）。UCSDI将通过1)心脏电流和心电位的直接3D成像，为心律失常和其他心脏疾病的消融治疗提供图像指导；2)增强的空间分辨率主要由超声焦点的大小决定；3)与脉冲回波超声（超声心动图）自动共配准，用于覆盖心脏解剖和运动的电流图。以下具体目标是验证这一假设的核心。SA.1。提高UCSDI系统硬件和软件的安全性。确定灵敏度和分辨率的基本限制。本项目将极大地改进我们现有的UCSDI系统，确定使用UCSDI绘制心脏激活波的灵敏度和空间分辨率的限制，并证明使用临床心内导管的可行性。一个成功的结果将导致为期5年的更新，重点是体内研究和转化到手术室。公共卫生相关性：该提案将开发3D超声电流源密度成像（UCSDI），这是一种基于超声和导电组织之间相互作用的新模式，用于绘制心脏电活动。一个优化的成像系统将极大地促进和加强心脏电生理制图，以治疗心律失常。

DESCRIPTION (provided by applicant): Recurrent cardiac arrhythmia is a serious health concern affecting more than 4 million Americans and accounts for 20% of all deaths related to heart disease. In advanced cases when drug therapy is ineffective, arrhythmias are often treated with resynchronization or ablation therapy. Intracardiac ablation procedures to correct drug-resistant arrhythmias depend on accurate maps of the cardiac activation wave. Despite global success of interventional cardiac surgery for treatment of arrhythmias, electrophysiological (EP) mapping of the heart has significant limitations; for example, the complex and expensive procedure is prone to image registration errors, not effective for identifying transient arrhythmias, and has relatively poor spatial resolution (5-10 mm). To overcome several limitations and dramatically improve EP mapping procedures, we propose a novel modality for real-time imaging of current flow and biopotentials in the heart. As such, this project would develop Ultrasound Current Source Density Imaging (UCSDI) to greatly enhance and facilitate EP mapping of the heart. UCSDI is based on an acoustoelectric (AE) interaction between local pressure and resistivity to remotely detect current flow in tissue. As we have demonstrated in a variety of preparations, ultrasound passing through tissue generates a voltage modulation (the AE signal) close to the ultrasound frequency and proportional to the local current density. UCSDI would facilitate image guidance during ablation treatment of arrhythmias and other cardiac disorders through 1) direct 3D imaging of current flow and cardiac potentials in the heart; 2) enhanced spatial resolution determined primarily by the size of the ultrasound focus; and 3) automatic co-registration with pulse echo ultrasound (echocardiograms) for overlaying current flow maps with cardiac anatomy and motion. The following specific aims are central for testing this hypothesis. SA.1. Enhance UCSDI system hardware and software SA.2. Determine fundamental limits of sensitivity and resolution SA.3. Interface UCSDI system with commercial intracardiac catheter This project would dramatically improve our existing UCSDI system, identify limits of sensitivity and spatial resolution for EP mapping of the cardiac activation wave using UCSDI, and demonstrate feasibility using a clinical intracardiac catheter. A successful outcome would lead to a 5-year renewal focusing on in vivo studies and translation to the operating room. PUBLIC HEALTH RELEVANCE: This proposal will develop 3D ultrasound current source density imaging (UCSDI), a new modality based on an interaction between ultrasound and conductive tissue, to map electrical activity in the heart. An optimized imaging system would greatly facilitate and enhance electrophysiological mapping of the heart for treatment of arrhythmias.