Click on image to view larger version.

Figure 2 The tracings from the top: electrocardiogram lead II; a His bundle recording (Hb); bipolar electrograms recorded from the distal electrode pair (D-2) of the catheter along the left atrium toward the SVC and the RA close to the FP (D-2) toward the RA appendage. In the baseline state (A), with no stimulation applied to the FP containing the AG, 10 atrial premature depolarizations (A₂-A₁₁) delivered just outside the local refractory period at the RSPV induced three beats of atrial tachycardia (AT). (B) During the delivery of 1.5 V to the AG, six atrial extra-stimuli applied with the same coupling (120 ms) to the RSPV induced atrial fibrillation (AF). Other abbreviations as in Figure 1.