Objectives: The mechanism of the recurrence of atrial fibrillation after pulmonary vein ablation was evaluated.
Methods: Eighty patients with atrial fibrillation underwent pulmonary vein ablation. If extrasystoles or atrial fibrillation initiations were frequent, focal ablation was performed at the site of the earliest activation. If the patient had little or no ectopy, all pulmonary veins with distinct and late pulmonary vein potentials were targeted for pulmonary vein isolation, which was achieved by minimal segmental ablation limited to the ostial site with the earliest pulmonary vein potentials.
Results: Focal ablation or pulmonary vein isolation was performed in 42 and 38 patients, respectively. After focal ablation, atrial fibrillation recurred in 23 patients and re-ablation was performed in 10:7 at sites near the previous source, 2 at a different part of the same pulmonary vein, and 1 at a different pulmonary vein. After pulmonary vein isolation, atrial fibrillation recurred in 19 patients and re-ablation was performed in 14:8 due to recovery of atrio-pulmonary vein conduction, 3 at non-pulmonary vein foci, 2 at pulmonary vein ostia proximal to the previous pulmonary vein isolation, and 1 at a different pulmonary vein.
Conclusions: After focal ablation, atrial fibrillation recurred from other foci in the same pulmonary vein or other pulmonary veins. Therefore, three or four pulmonary veins should be isolated. However, atrial fibrillation recurred after pulmonary vein isolation due to the recovery of atrio-pulmonary vein conduction or non-pulmonary vein foci. Further development of new mapping and ablation systems to detect the foci and create a complete lesion at the pulmonary vein ostium may be necessary.