Redo ablation results
Among the 55 patients with recurrence after the index catheter ablation procedure, 42 patients underwent a redo ablation procedure. Of the 12 patients with AT recurrence who underwent a redo ablation, AT persisted at the beginning of the procedure in 8 (66.6%) patients, and the type of AT was identified in all patients. Perimitral AT circulating around the mitral annulus was the most frequently confirmed type (4 patients). Of these four patients with perimitral AT recurrence, cryoballoon ablation of the LA roof was performed in the index ablation procedure in three patients. Roof-dependent AT, which contained the LA roof in the reentrant circuit, was observed in two patients, who both underwent cryoballoon ablation of the LA roof in the index ablation procedure. PV gap-related AT was confirmed in the other two patients.
The durability of each lesion created in the index ablation procedure is described in Figure 4. The prevalence of the patients in whom all PVs were confirmed to be durable was 57.1% (24/42 patients). Complete conduction blocks at the LA roof, LAPW bottom, and CTI were confirmed to be durable in 72.2% (18/25), 38.1% (8/21), and 56.8% (21/37) of patients, respectively. The rates of lesion durability of the PVI and LA roof lines without touch-up ablations were 59.4% (19/32) and 73.9% (17/23) of patients, respectively. When the percentages of the lesion durability between the patients with AT recurrence (25.0%) and those without AT recurrence (29.4%) were compared, the prevalence of LA roof-line recurrence was comparable (p=1.00). At the beginning of the session, the ratio of scar area to LAPW area was significantly higher (p<0.01) in the patients who had undergone cryoballoon ablation (66.3 [45.8–83.1] %) of the LAPW in the index ablation as compared to those who had not (12.2 [2.1–26.3] %).
Additional linear ablation at the LAPW, including the LA roof line, was performed in 35 (97.2%) of 36 patients whose LAPW was not isolated at the beginning of the redo ablation procedure. MI ablation was performed in 19 (45.2%) of 42 patients. Of 41 patients who underwent follow-up after-redo ablation procedure, 26 (63.4%) were free from atrial arrhythmias after the redo ablation procedure.