Methods: We included 34 patients (Age 64±14, male 76%) and 131PVs: 34 Left superior(LS) PVs, 32 Left inferior(LI) PVs, 34 Right Superior(RS) PVs, 31 Right inferior(RI) PVs) that underwent catheter ablation using Rhythmia mapping system for atrial fibrillation ( paroxysmal AF, 10; persistent AF, 4). Mapping of the left atrium was performed using a catheter after 1st ablation procedure(cryoballoon ablation, 22; radiofrequency ablation 12). Mapping was conducted twice with different atrial pacing sites, that is, coronary sinus(CS) ostium and left atrial appendage(LAA). For each map, we identified the earliest activation site and measured the difference between the two maps. We defined the PV reconnection according to the findings of ring catheter and the difference of conduction pattern by the 2 pacing sites. We compared the amplitude of PV potential and the difference of earliest activation sites between the reconnected PVs and isolated PVs. We also compared the characteristics of the gap between the initial radiofrequency and cryoballoon ablations.
Results: 41 PVs had reconnection gaps (G group) and 90 PVs had no reconnection gaps (NG group). Reconnected gaps included 5 LSPV, 7 LIPV, 17 RSPV, and 12 RIPV. G group had significantly shorter distance between the earliest activation site of the two maps than the NG group (G group vs NG group; 5.22±0.53mm vs 17.08±0.36mm, p<0.0001). The voltage of the G group had higher voltage than the NG group (G group vs NG group; 0.61±0.05mV vs 0.04±0.03 mV, p<0.0001). A circular catheter failed to observe 6 reconnected PVs (17%). Initial procedure was cryoablation in 20 PVs and radiofrequency ablation in 21 PVs. The width of PV gap was significantly wider in the initial radiofrequency ablation compared to cryoballoon ablation(10.8±0.87vs 8.1±0.85 mm, p=0.03).
Conclusion: Differential atrial pacing maneuver and the voltage of the PV potentials may be helpful to identify PV reconnection gaps with tiny PV potential which could not be detected by the ring catheter. If the amplitude of potentials is less than 0.07mV, the PV can be usually considered no PV gap.