Pitfalls in the definition of complex fractionated atrial electrograms for atrial fibrillation studies

[First paragraph] We read with great interest the study by Baher and colleagues.1 Their work helps to consolidate the use of recurrence quantification analysis (RQA) in the investigation of cardiac dynamics during atrial fibrillation (AF). It also motivates further discussion on creative methods and biomarkers for studying such complex cardiac disorder.