Catheter ablation of fractionated electrograms for atrial fibrillation: does it improve outcomes and can it be refined based on electrogram morphology or knowledge of the remodelling process?.

Abstract

Catheter ablation complex or fractionated atrial electrograms (CFAE) may improve outcomes for persistent AF. However, it is unclear whether CFAE are important in maintaining AF or whether targeting of CFAE can be refined based on electrogram morphology or knowledge of the remodelling process. A detailed classification of CFAE was described. Assessment of 100 CFAE by visual inspection in real time correlated well with detailed offline measurement. Targeting of different CFAE morphologies in 20 patients with persistent AF caused cycle length prolongation only with ablation of certain CFAE morphologies. Therefore, targeting CFAE is not simply atrial de-bulking, certain CFAE morphologies are more important for maintaining AF. A computer model was established to simulate LA wall stress using a 3D reconstruction of the chamber from CT imaging. Electrophysiologic data was acquired in 19 patients in persistent AF and compared to simulated wall stress data. Peaks in wall stress were associated with areas of low voltage suggestive of focal remodelling. CFAE were not associated with peaks in wall stress or areas of remodelling. Wall stress did not determine whether ablation of CFAE caused cycle length prolongation. Long term outcome of catheter ablation for AF was good with little late recurrence. Outcome for persistent AF was improved by targeting CFAE in addition to pulmonary vein isolation and may reduce late recurrence