Incidence and electrophysiologic properties of dissociated pulmonary vein activity following pulmonary vein isolation during catheter ablation of atrial fibrillation.

INTRODUCTION: pulmonary veins (PV) play an important role in the arrhythmogenesis of atrial fibrillation (AF). Catheter-based PV isolation is one of the primary treatments for symptomatic drug refractory AF. Following electrical isolation, isolated rhythms in the PV are encountered. The aim of this study was to assess the frequency of postisolation PV activity and classify the different rhythms observed. METHODS AND RESULTS: this single center prospective study sought to assess the dissociated activity in the PVs following their isolation during AF ablation. In 100 consecutive patients (60 paroxysmal, 40 persistent) undergoing AF ablation, dissociated PV activity was recorded using a multielectrode mapping catheter following antral PV isolation. The dissociated PV activity was classified as (1) silent, (2) isolated ectopic beats, (3) ectopic rhythm, and (4) PV fibrillation. All the PVs were successfully isolated in all the patients. In 91 of 100 patients, there was dissociated activity in at least 1 isolated ipsilateral PV group. There was no significant difference in spontaneous PV activity between patients with paroxysmal and persistent AF (91.7% vs 90%, P = 1.0). Among the 200 isolated ipsilateral PV groups, 64 of 200 (32%) were silent, 86 of 200 (43%) demonstrated isolated ectopic beats, 41 of 200 (20.5%) had ectopic rhythms and 9 of 200 (4.5%) had PV fibrillation. The average cycle length of the PV ectopic rhythm was 2594 ± 966 ms (range 1193-4750 ms). CONCLUSIONS: following PV isolation, a majority of patients demonstrate dissociated activity in at least 1 PV. This finding was evident in patients with both paroxysmal and persistent AF.