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

描述(申请人提供)：复发性心律失常是一个严重的健康问题，影响着400多万美国人，占所有与心脏病有关的死亡人数的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化或消融治疗。纠正耐药性心律失常的心内消融术依赖于准确的心脏激活波图。尽管介入心脏手术在治疗心律失常方面取得了全球的成功，但心脏的电生理(EP)标测仍有很大的局限性；例如，复杂而昂贵的程序容易出现图像配准错误，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)。为了克服一些局限性，并显著改进EP标测程序，我们提出了一种新的模式，用于实时成像心脏中的电流和生物电势。因此，该项目将开发超声电流源密度成像(UCSDI)，以极大地增强和促进心脏的EP标测。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流动。正如我们在各种制剂中所展示的那样，超声通过组织时产生的电压调制(声发射信号)接近超声频率，并与局部电流密度成正比。UCSDI将有助于在消融治疗心律失常和其他心脏疾病时提供图像指导，方法是：1)直接对心脏内的电流和心脏潜力进行3D成像；2)增强空间分辨率，主要由超声病灶的大小决定；以及3)与脉冲回声超声(超声心动图)自动配准，将当前血流图与心脏解剖和运动相叠加。以下具体目标是检验这一假说的核心。SA.1。增强UCSDI系统硬件和软件SA2.确定灵敏度和分辨率的基本极限。该项目将极大地改进我们现有的UCSDI系统，确定使用UCSDI对心脏激活波进行EP标测的灵敏度和空间分辨率极限，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以活体研究和手术室翻译为重点的5年续签。与公共健康相关：这项提议将开发3D超声电流源密度成像(UCSDI)，这是一种基于超声和传导组织之间相互作用的新模式，以绘制心脏中的电活动图。优化的成像系统将极大地促进和加强心脏的电生理标测，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.