Aims: Complete pulmonary vein isolation (CPVI) can be achieved by continuous circular lesions (CCL) around the ipsilateral pulmonary veins (PVs) guided by a 3D-mapping system. We investigated whether CPVI can be achieved with a single CCL around the isplilateral PVs without recording PV activity during ablation.
Methods and results: Fifty patients with atrial fibrillation underwent ablation of CCLs around ipsilateral PVs guided by 3D mapping. One or two Lasso catheters were placed within the PVs. Lasso tracings were hidden to physicians during ablation. After completion of CCLs, Lasso tracings were evaluated. If PV activation was present, conduction gaps (CGs) were identified and ablated with guidance by the local electrogram and the Lasso catheter(s). In 21 patients (42%), CPVI was achieved after ablation of a single CCL around ipsilateral PVs. Pulmonary vein isolation was achieved in 43 patients (86%) in the right-sided PVs and in 21 patients (42%) in the left-sided PVs. In the remaining patients, there were eight CGs in right-sided CCLs and 40 CGs in left-sided CCLs. Conduction gaps along the left CCLs were found at the ridge between the PV ostia and the left atrial appendage in 27 out of 40 CGs (68%). Mean time from the P-wave onset to the earliest PV potential was 112±35 ms in the presence of a CG at the roof, and 166±59 ms in patients with CGs at other locations in left-sided CCLs (P<0.05).
Conclusion: Complete pulmonary vein isolation is difficult to achieve with a single CCL around ipsilateral PVs without continuous recording of PV activation during ablation.