2.3 | Acute endpoints
The acute endpoints of the procedure include complete PVI, LAPW isolation, and bidirectional linear block (CTI block and MI block) after a 20-minute waiting period. PVI and LAPW isolation were confirmed by the absence of electrograms in PV and LAPW (Figure 2C ). Bidirectional MI block was confirmed by the following criteria: 1)Proximal-to-distal CS activation pattern when pacing at the left lateral ridge; 2) Longer SA interval at the left lateral ridge when pacing at the distal CS compared to pacing at the proximal CS (Figure 3 ). Bidirectional CTI block was confirmed by the activation from the right atrium lateral wall to the ablation line when pacing at proximal CS. The SA interval near the ablation line was longer than at the right atrium lateral wall when pacing at proximal CS (Figure 4 ).