Circumferential pulmonary vein isolation: the role of key target sites.

AIMS: Circumferential pulmonary vein isolation (CPVI) had been proved effective for treating atrial fibrillation (AF). However, the achievement of pulmonary vein (PV) isolation was sometimes challenging. PVs could not be isolated until some key target sites (KTSs) were ablated thoroughly. The aim of our study was to explore the distribution of KTSs.

METHODS AND RESULTS: Four hundred and fifty-two cases (271 males, mean age 62.5 +/- 12.6 years) with drug-refractory AF were enrolled for catheter ablation. CARTO-guided CPVI was performed in all cases with one circular catheter for verification of PVs isolation. Target sites where PV potentials delayed, conduction sequence changed, slowed down, or isolated were defined as KTSs. From 452 CPVI procedures, 1520 KTSs were identified; 813 of which were located at left PV antrums and 707 were at right PV antrums. KTSs at left PV antrums were most commonly situated at anterior wall (63%), while KTSs at right PV antrums were most commonly situated at posterior wall (66.2%). Additional gaps ablation was performed for left PVs in 344 cases and for right PVs in 248 cases owing to incomplete PVs isolation by a single attempt of CPVI. One thousand one hundred and fifty-eight KTSs were identified, 662 of which were located at left PV antrums and 496 were at right PV antrums. At the anterior wall, 66.1% of left PV KTSs were located, and 67.9% of right PV KTSs were located at the posterior wall. Out of 1158, 961 (82.99%) KTSs were predicted correctly by circular mapping. PV isolation could not be achieved until some KTSs were ablated by higher power, longer duration, and higher irrigation rate than usual.

CONCLUSION: KTSs during CPVI were most commonly situated at the anterior wall of left PVs and at the posterior wall of right PVs. Circular mapping within ipsilateral PVs' ostia could accurately predict the location of KTSs. Some KTSs must be ablated thoroughly by applying higher power, longer duration, and higher irrigation rate than usual to achieve PV isolation.