Stability of conduction patterns in persistent atrial fibrillation

There is a growing interest and practice of guidance of catheter ablation of atrial fibrillation (AF) by specific conduction patterns (rotors, point sources, regions of conduction slowing). Temporal stability of conduction patterns in AF has not been studied in detail. Saventeen patients were enrolled for de novo mapping and ablation of persistent AF. Prior to pulmonary vein isolation, left atrial (LA) high density maps were collected using a 20 polar circular catheter. Conduction pattern stability was assessed using Mean Phase Coherence (MPC) of atrial electrograms. Stability was defined as the presence of several consecutive conduction patterns correlated with MPC>0.85 tolerance which constituted an individual stable pattern (SP). LA surface coverage by SP and percentage of the time SP were present strongly depends on SP definition. For SP defined as a train of at least 3 consecutive activations, SP were found on 82% of mapped LA surface and were present 26% of the mapping time. However, if SP is defined as a train of at least 20 similar activations, the coverage drops to 15% and time SP was present to 6.5%. In conclusion, conduction patterns during AF are short lasting. Long recordings should be analyzed before deciding on the ablation target based on specific conduction pattern.