Abstract 4114: Identification of Gap Lesions Following Failed Atrial Fibrillation Ablation: Using Three-Dimensional Delayed Enhancement MRI to Guide Re-ablation Procedure
Objectives. Pulmonary vein antrum (PVA) isolation is a common ablation strategy to treat patients with atrial fibrillation (AF). Incomplete lesion formation around the PVA is thought to contribute to recurrence of AF. We report a new multi-step approach to ensure complete PVA scarring by using 3D delayed enhancement MRI (DE-MRI) models of the LA to show regions needing ablation during repeat procedure.
Methods. Five patients who suffered AF recurrence following PVAI elected to undergo a second procedure. All 5 patients received DE-MRI scans 3 months following each procedure. 3D segmentation of the LA was performed to evaluate for complete PVA scarring. Application of a color look-up table was used to illuminate scar tissue. Regions of healthy PVA myocardium was marked following the failed ablation and targeted during repeat procedure.
Results. All patients showed incomplete PVA scarring after the first ablation. All patients had increased PVA scarring following the repeat procedure. 4 (80%) patients were free of AF (determined by 8 day Holter recordings, ECG and event monitoring) at 3-month follow-up. The figure⇓ below shows lack of continuous scar (orange/white) around the left and right PVA following the failed procedure. Gap lesions of healthy myocardium (blue) were identified and targeted (yellow arrows) prior to repeat ablation. Following the successful repeat procedure, all four PVA had continuous scar lesions.
Conclusion. 3D DE-MRI models of the LA may identify gaps in RF lesions following failed PVA isolation. These 3D models may assist in procedure planning for the second ablation procedure by identifying the regions necessary for re-ablation.