Electrophysiological findings during AF re-ablation: Extending from PV reconnection to sequential bipolar voltage map information.

BACKGROUND: Left atrial substrate modification targeting low voltage zones (LVZ) is an ablation strategy that - in addition to pulmonary vein isolation (PVI) - tries to eliminate arrhythmogenic mechanisms harbored in such tissue. Electrophysiological findings at re-ablation include (i) PV re-connection, (ii) reconnection over previous substrate ablation, and (iii) de-novo LVZ.

OBJECTIVE: To study, prevalence and contribution of these arrhythmogenic electrophysiological entities in patients with AF recurrences.

METHODS: Consecutive patients with highly symptomatic AF undergoing index and re-ablation were included (n=113). In all patients PV reconnection, re-connection over previous substrate ablation and spontaneous de-novo LVZ were quantitatively assessed and integrated into an individual re-ablation strategy. Follow-up was based on continuous device monitoring.

RESULTS: At re-do procedure, 45 out of 113 (39.8%) patients showed PV re-connection as the only electrophysiological abnormality. Re-conduction over previous lines was the only electrophysiological abnormality in 8 out of 113 (7.1%) patients. Spontaneous de-novo LVZ was the only electrophysiological abnormality in 12 out of 113 (10.6%) patients. Combined findings of PV re-connection, line re-conduction, and/or spontaneous de-novo LVZ were seen in 40 out of 113 (35.4%) patients. No detectable electrophysiological abnormality was observed in 8 out of 113 (7.1%) patients. In univariate analysis none of the tested electrophysiological characteristics independently predicted the outcome after re-do.

CONCLUSIONS: In patients undergoing re-ablation we could show that re-conduction over previous substrate ablation as well as development of new low voltage areas are frequent findings besides classical PV reconnection - without a clear leading cause for recurrences. These findings impact re-ablation strategies as well the strategic focus during index procedures. This article is protected by copyright. All rights reserved.