Abstract 21223: Radiofrequency Atrial Ablation and Visualization of Lesion Formation Under Real Time MRI Guidance
Introduction: We assessed the feasibility of a novel 3-Tesla real time-MRI (RT-MRI) based ablation model and lesion visualization during ablation.
Methods: Ten swine were taken to the interventional 3T MRI suite and a MRI compatible ablation catheter was visualized under RT-MRI and advanced into right or left atrium (figure 1). Intracardiac electrograms (EGMs) were recorded and pacing maneuvers performed during MRI scanning (figure 2). The catheter tip location and position were defined using with a Turbo-Flash sequence, with this information points in a 3D shell, obtained from angiography segmentation, were tagged. Lesion formation was then visualized using a T2w HASTE during RF energy delivery.
Results: In all ten animals a series of lesions (figure 3) in the right and/or left atrium were delivered under and during real time MRI scanning. Macroscopic examination and ex-vivo MRI (figure 3) was then performed to correlate ablation location and lesion formation. T2w enhancement at 20 seconds from RF beginning correlated with ex-vivo lesion size (figure 4).
Conclusions: RF energy delivery and visualization of atrial myocardium lesion formation as they form under real time MRI imaging guidance is feasible. Real-time MRI guided ablations would improve safety and efficacy of interventional electrophysiology procedures.
- Ablation, radiofrequency
- Magnetic resonance imaging
- Atrial arrhythmias
- Arrhythmia mapping
- Atrial fibrillation
- © 2010 by American Heart Association, Inc.