EGM (CFAE)-guided ablation for AF
The original CFAE ablation study, reported by Nademanee et al., demonstrated high acute AF termination rates of 82% and arrhythmia-free survival in three quarters of patients at one-year follow-up.7 Haissaguerre et al. subsequently proposed EGM-guided ablation targeting fractionated, rapid and gradient signals in addition to linear ablation, an approach associated with a high acute AF termination rate.8 The concept of EGM or CFAE-guided ablation involves targeting AF driver sources represented by pivot points of wavelets, continuous re-entry of fibrillation waves with relatively short cycle lengths, and heterogenous temporal and special distribution.30 Of note however, identification of CFAE signals is quite subjective (e.g. definition of fractionated electrograms) and therefore this strategy was not consistent and not formally established, even with the use of automatic analysis algorithms incorporated into 3D-EAM systems.21,31 A recent large meta-analysis did not demonstrate an incremental beneficial effect of CFAE ablation in addition to PVI compared with PVI alone in PsAF patients.9 It is possible that in addition to critical AF drivers CFAEs represent also passive activations, such as signal artifact, double potential, slow conduction and wavebreak.15,32 In the present study, EGM-guided ablation, using the Bordeaux approach,8 was performed by visual and manual inspection by one sufficiently experienced operator. However, methodological differences might be associated with lower AF termination rate (40%) and poor clinical outcome (AF/AT-free survival of 38% /1.5 years). An important point to consider when comparing outcomes of CFAE ablation is the inter-operator variability CFAE identification.