Novel Catheter for Treatment of Ventricular Tachycardia

描述（由申请人提供）：美国每年有30万人死于心源性猝死。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。射频消融术虽然能成功治疗室上性心动过速，但由于常规射频消融术导管不能治疗足够大容量的心肌，因此不能成功治疗室性心动过速。在这个项目的第一期，我们已经证明了盐增强消融的可行性。我们将使用通过心肌输注温盐水（同时应用射频或激光加热能量）将组织热传输增加20倍或更多。我们已经证明，这种方法可以使心肌热损伤的体积增加12倍。这些病变能够治疗全层心肌，因此有望治疗室性心动过速。我们将在第二阶段项目中继续开发该系统。基于第一阶段的结果，我们将继续使用生理盐水增强射频消融。我们将开发一种可操纵的导管，其尖端将有一个多孔射频电极，将被插入心肌。导管将有一个中央管腔，带射频加热器，在将生理盐水注射到心肌瘤之前加热生理盐水。我们将在梅奥诊所和布里格姆妇女医院的室性心动过速动物模型的临床前研究中验证这种原型导管和系统。

DESCRIPTION (provided by applicant): 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. Radiofrequency ablation, which successfully treats supraventricular tachycardia, is not successful at treating ventricular tachycardia because conventional RF ablation catheters cannot treat a large enough volume of myocardium. In Phase 1 of this project, we have demonstrated the feasibility of saline-enhanced ablation. We will have used infusion of warm saline through the myocardium (simultaneous with the application of radiofrequency or laser 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 myocardium by a factor of 12. These lesions are capable of treating the full thickness of the myocardium, and therefore show promise toward treatment of ventricular tachycardia. We will continue the development of this system during this Phase 2 project. Based on the Phase 1 results we will continue our development using saline enhanced radiofrequency ablations. We will develop a steerable catheter that will have a porous radiofrequency electrode at the tip, which will be inserted into the myocardium. The catheter will have a central lumen with an RF heater to heat the saline before injecting it into the myocardiurn. We will qualify this prototype catheter and system in preclinical studies of ventricular tachycardia in animal models at the Mayo Clinic and the Brigham and Women's Hospital.