Right-to-left frequency gradient during atrial fibrillation initiated by right atrial ectopies and its augmentation by adenosine triphosphate: Implications of right atrial fibrillation

Background A left-to-right dominant frequency (DF) gradient commonly exists in paroxysmal atrial fibrillation (AF). AF initiated by right atrial (RA) ectopy (AF-RAE) is rare. Objective This study aimed to investigate characteristics of AF-RAE using pharmacological maneuvers and spectral analysis. Methods Seventy-nine consecutive patients referred for catheter ablation of paroxysmal AF were enrolled. Infusions of isoproterenol and adenosine triphosphate (ATP) were used to induce AF. Patients with AF-RAE and patients with AF initiated only by pulmonary vein (PV) ectopies were classified into the RA-ectopy group (n = 7[9%]) and PV-ectopy group (n = 32[41%]), respectively. ATP was also injected during ongoing AF to unmask the driver of AF. High RA, coronary sinus, and PV-left atrial junction electrograms and electrocardiogram lead V 1 underwent spectral analyses. Results Patients in the RA-ectopy group were younger (51 ± 13 years vs 63 ± 7 years; P = .01) and more commonly had a family history of AF (71% vs 9%; P P P P P Conclusion A rare type of paroxysmal AF initiated by RA ectopy may be maintained by a reentrant driver localized in the RA (so-called RA fibrillation).