Figure 1.
Right atrial FIRM mapping and ablation during AF. A: Basket and ablation catheters in the right atrium during AF (anteroposterior fluoroscopy). B: Counterclockwise rotor in posterolateral right atrium centered over C3, with collision beyond the spiral arms (indicated by white double lines; supplementary movie). C: Electrograms around the RA rotor site, indicating counterclockwise rotation with variability at CL ≈ 177 ms. D: FIRM ablation at RA rotor terminates AF to sinus rhythm within 30 seconds. ABL = ablation electrogram; AF = atrial fibrillation; CL = cycle length; CSP = proximal coronary sinus; FIRM = focal impulse and rotor modulation; RA = right atrial.