Novel Catheter for Treatment of Ventricular Tachycardia

描述(申请人提供)：美国每年有30万人死于心脏性猝死。其中一半以上的死亡是由包括室性心动过速在内的心律失常引起的。射频消融术成功地治疗室上性心动过速，但由于传统的射频消融导管不能治疗足够大的心肌体积，因此在治疗室性心动过速方面并不成功。在这个项目的第一阶段，我们已经证明了盐水增强消融的可行性。我们将通过心肌注入温盐水(同时应用射频或激光加热能量)，将组织的热传输增加20倍或更多。结果表明，这种方法可以使心肌热损伤的体积增加12倍。这些损伤能够治疗心肌的全部厚度，因此在治疗室性心动过速方面显示出良好的前景。在这个第二阶段的项目中，我们将继续开发这个系统。基于第一阶段的结果，我们将继续使用盐水增强型射频消融术进行开发。我们将开发一种可导向的导管，它的尖端将有一个多孔的射频电极，它将被插入到心肌中。导管将有一个带有射频加热器的中央管腔，在将生理盐水注入心肌之前将其加热。我们将在梅奥诊所和布里格姆妇女医院进行的室性心动过速动物模型的临床前研究中对该原型导管和系统进行鉴定。

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.