NOVEL CATHETER FOR TREATMENT OF VENTRICULAR TACHYCARDIA

在美国，心脏性猝死每年导致30万人死亡。这些死亡中有一半以上是由心律失常引起的，包括室性心动过速。目前尚无安全、有效、廉价的方法治疗大多数室性心动过速。使用射频或激光加热的热消融可以有效地治疗室上性心动过速，但病变太小，无法治疗大多数VT，特别是那些起源于梗死疤痕的VT。两种效应限制了病变的大小。首先，能量在治疗工具周围的薄组织层中被吸收。其次，热传导太小，无法将能量更深地携带到组织中。我们已经开发了盐水增强消融，其使用通过心肌灌注温盐水（同时应用加热能量）以将组织热传输增加20倍或更多。我们已经表明，这种方法可以增加体积的热损伤肝癌的一个因素100。我们将调整我们的系统，以测试其对心肌射频和激光加热的改善。产生最大、最深病变的方法将用于II期的继续开发。拟议的商业应用：该项目的目标是开发一种系统和相关的治疗方案，可以安全地加热大面积的心肌。这将有助于治疗室性心动过速，特别是心肌梗死后的VT，这通常需要大的消融损伤。

Sudden cardiac death kills 300,000 people in the United States yearly. More than half of these deaths are caused by arrhythmias including ventricular tachycardia. Currently there is no safe, effective and inexpensive method for treating most ventricular tachycardias. Thermal ablation using radiofrequency or laser heating can effectively treat supraventricular tachycardia, but the lesions are too small to treat most VTs, especially those that originate from infarct scars. Two effects limit the lesion size. First, the energy is absorbed in a thin layer of tissue surrounding the therapy tool. Second, thermal conduction is too small to carry the energy deeper into the tissue. We have developed saline-enhanced ablation, which uses infusion of warm saline through the myocardium (simultaneous with the application of heating energy) to increase the tissue thermal transport by a factor of 20 or more. We have shown that this method can increase the volume of thermal lesions in liver cancer by a factor of l00. We will adapt our system to test the improvement it provides to RF and laser heating of myocardium. The method that creates the largest, deepest lesions will be used for continued development in Phase 2. PROPOSED COMMERCIAL APPLICATIONS: The goal of this project is to develop a system and associated therapy protocols that can safely heat large regions of myocardium. This will be useful for treating ventricular tachycardia, especially VT following myocardial infarction, which typically requires large ablation lesions.