Pearls and pitfalls in catheter ablation of persistent atrial fibrillation

Catheter ablation of atrial fibrillation (AF) has evolved over the past 20 years from being a novel, unproven procedure to a commonly performed procedure. Triggers are important for the initiation of AF and a suitable substrate is important for perpetuation of AF. Remodeling, including electrical and structural remodeling, is common in patients with persistent AF. Therefore, targeting the remodeled atrium is a critical issue during persistent AF ablation. However, ablation outcomes remain suboptimal despite aggressive substrate modification. Empirical linear ablation is not recommended because of the difficulty in achieving complete linear block and it is recommended only if macroreentry tachycardia develops during the procedure. Complex fractionated atrial electrogram (CFAE) ablation is recommended in the Heart Rhythm Society Consensus Document but efficacy has been limited in long-term follow-up studies. Rotor ablation is controversial. A combined approach using CFAE, similarity and phase mappings with rotor identification may be helpful in searching for AF sources and subsequent substrate ablation. Nevertheless, more prospective randomized studies are required to validate efficacy and safety.