New generation of catheters for treatment of atrial fibrillation

描述(申请人提供)：房颤仍然是最常见的心律失常。它与较低的生活质量和较高的发病率和死亡率有关。以消除心房颤动为目的的冷冻治疗和射频消融已成为一种主流的治疗选择。它们会产生损伤，阻止电活动从异常活动部位的传播，包括肺静脉。今天，在心脏消融过程中实时监测组织损伤的手段有限。为了满足这一需要，我们研究了内源性NADH的荧光作为消融过程中组织损伤的活标记物，并在血液灌流的动物心脏中证实了这种方法的可行性。STR第一阶段的支持将为我们提供必要的资金，以加快该项目进入下一阶段。研究将在大小完全麻醉的开胸动物身上进行。Aim1的目标是比较激光和LED照明的有效性、内部和外部摄像机的灵敏度和空间分辨率，测试充气气球的形状和材料，并将所有组件安装在直径为12Fr(4 Mm)的导管的管腔内。在目标2中，由LuxCath设计的几个重复的导管将被带到GWU外科内窥镜研究所(WISE)的外科套件进行测试。NADH荧光图像将被实时获取，以显示包括肺静脉在内的各种临床相关部位的消融病变之间的活组织间隙。电活动记录将与NADH图像相关联，以将消融间隙与消融后折返的发生联系起来。第一阶段的近期目标是开发一种临床前的独立可视化导管，可以在房颤消融过程中使用，以评估肺静脉开口周围的心脏病变。最终，新一代独立的可视化导管以及具有可视化能力的消融导管将被开发出来，从而能够实时地可视化 在消融时消融组织或使用相同的设备进行消融。这些新的成像技术将为更容易、更快、更安全、更具成本效益和更可靠的微创房颤消融手术铺平道路。

DESCRIPTION (provided by applicant): Atrial fibrillation remains the most commonly occurring cardiac arrhythmia. It is associated with a lower quality of life and a higher rate of morbidity & mortality. Cryotherapy and radiofrequency catheter ablations for the purpose of eliminating atrial fibrillation have become a mainstream treatment option. They produce lesions that block the spread of electrical activity from the sites of abnormal activity, including the pulmonary veins. Today, there are limited means for real-time monitoring of tissue injury during cardiac ablation procedures. To address this need, we studied the fluorescence of endogenous NADH as a live marker of tissue injury during the ablation procedure and have confirmed the feasibility of this approach in blood perfused animal hearts. STTR Phase I support will provide us with the necessary funds to accelerate the project into its next phase. Studies will be conducted in small and large, fully-anesthetized open-chest animals. The goals of Aim1 are to compare the effectiveness of laser vs LED based illumination, sensitivity and spatial resolution of internal vs external cameras, and to test the shape and material for the inflatable balloons and to fit all the components within lumen of a 12Fr (4mm) diameter catheter. In Aim 2 several iterations of catheters designed by LuxCath will be brought to the GWU Institute of Surgical Endoscopy (WISE) surgical suite for testing. Images of NADH fluorescence will be acquired in real time to visualize gaps of viable tissue between ablation lesions at various clinically relevan sites, including the pulmonary veins. Electrical activity recordings will be linked to NADH images to correlate ablation gaps to the occurrence of post-ablation reentries. The immediate goal of Phase I is to develop a pre-clinical stand-alone visualization catheter that can be used during AF ablation procedures to evaluate the cardiac lesions around the ostia of the pulmonary veins. Ultimately, a new generation of stand- alone visualization catheters as well as ablation catheters incorporating visualization capabilities will be developed thus enabling real-time visualization of ablated tissue at the time of ablation or using the same device to perform the ablations. Such new imaging technologies will pave the way for easier, faster, safer, more cost-effective, and more reliable minimally invasive AF ablation procedures..