Abstract 2243: Real-Time Computed Tomography (RT-CT) for Guidance of Catheter Navigation, Transseptal Puncture and Anatomically Targeted Radiofrequency Ablation

Abstract

Background: Recent ablation strategies for complex arrhythmias such as atrial fibrillation or ischemic ventricular tachycardia are increasingly based on anatomic considerations. While fluoroscopy and 3D-mapping systems are widely used to guide these ablations, they are limited by poor soft tissue visualization and the lack of real-time anatomic data. Therefore, this study sought to evaluate if real-time computed tomography (RT-CT) could overcome these limitations and guide catheter navigation, transseptal puncture and anatomically targeted ablation. Methods: Catheter real-time guidance was assessed in 5 swine (40kg) using a 40-slice RT-CT. First, right/left heart catheterization was performed from the femoral vein and artery with the goal to access all cardiac chambers and the great cardiac vessels. Second, transseptal puncture was attempted with targeted ablations at pre-specified locations at the left lateral wall. Third, targeted ablation at the pulmonary vein (PV) orifice and repeat ablations at the right lateral wall were created to assess accuracy and precision, respectively. Fourth, creation of a straight ventricular four-point line was attempted. Necropsy was performed to assess possible complications and to compare the location of the ablation sites with the CT images. Results: Catheter navigation was performed safely from the femoral vein to the pulmonary artery and the femoral artery to the left ventricle. Misguided catheters to the renal vein, jugular vein, and carotid artery were correctly identified and removed. Transseptal puncture using a Brocken-brough needle was successfully performed and confirmed with anatomically targeted ablations at the left lateral atrial wall. Accuracy as assessed by PV ablations was in the range of 1–3mm. Repeat ablations in the right atrial wall revealed a precision of 2–3mm. Maximum deviation from a straight 4-point ventricular line was 2.8mm. No complications were seen at necropsy. Conclusions: Catheter navigation (in all four cardiac chambers) as well as transseptal puncture can be performed guided exclusively by RT-CT. Anatomically targeted ablations can be created with good accuracy and precision under real-time guidance. This suggests a possible role of RT-CT to guide ablation procedures.