Alterations of sympathetic dynamics after atrial fibrillation ablation by analysis sympathetic nerve activity provide prognostic value for recurrence and mechanistic insights into ablation.

Background: Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Success is associated with autonomic function modulation; however, the relationship between the changes after ablation is not fully understood. We aimed to investigate the effect of ablation on autonomic modulation by skin sympathetic nerve activity (SKNA) using conventional electrocardiogram (ECG) electrodes and to predict the treatment success. Methods: We enrolled 79 patients. We recorded neuECG for 10 min at 10 kHz before and after ablation. The NeuECG was bandpass-filtered (500-1,000 Hz) and integrated at intervals of 100 ms (iSKNA). iSKNA was averaged over different time windows (1-, 5-,10-s; aSKNAs), and burst analyses were derived from aSKNAs to quantify the dynamics of sympathetic activities. AF recurrence after 3 months was defined as the study endpoint. Results: Sixteen patients experienced AF recurrence after the ablation. For burst analysis of 1-s aSKNA, the recurrence group had a higher bursting frequency than the non-recurrence group (0.074 ± 0.055 vs. 0.109 ± 0.067; p < 0.05) before ablation. The differences between pre- and post-ablation of firing duration longer than 2 s were more in the non-recurrence group (2.75 ± 6.41 vs. -1.41 ± 5.14; p < 0.05), while no significant changes were observed in the percentage of duration longer than 10 s using 5-s aSKNA. In addition, decreases in differences in firing frequency and percentage of both overall firing duration and longer firing duration (> 2 s) between pre- and post-ablation were independently associated with AF recurrence and more area under receiver operating characteristics (ROC) curve in combination with CHADS2 score (0.833). Conclusion: We demonstrated the applicability of neuECG for determining sympathetic modulation during AF ablation. Decreasing sympathetic activity is the key to successful ablation.

Outcome of Circumferential Pulmonary Vein Isolation for Ablation of Atrial Fibrillation: A Single Center Experience.

BACKGROUND: Atrial fibrillation (AF) is the most common heart rhythm disorder in adults. Currently, use of the circumferential pulmonary vein isolation (CPVI) technique is the cornerstone of ablation therapy for paroxysmal atrial fibrillation. In this report, we described our ablation strategy and outcomes when treating a limited number of AF patients. METHODS: This study enrolled patients with paroxysmal or persistent AF that were resistant to at least one anti-arrhythmia drug. We used the CARTO XP system for electro-anatomic mapping, facilitated by left atrium multi-slice computed tomography imaging. The ablation strategy was to obtain CPVI by using an irrigation catheter and the end-point was complete entry and exit block at each pulmonary veins. AF recurrence was defined through review of symptoms and AF documentation via electrocardiography (ECG) or Holter ECG. RESULTS: From 2007 to 2011, 108 patients (76% paroxysmal AF) received ablation by means of our standard procedures, and the AF recurrence rate was 22% during a mean follow up of 20.6 ± 10.2 months. The major complication rate was less than 3% in all the patients that received AF ablation in our center. CONCLUSIONS: Our AF ablation results were comparable to those results reported in major electrophysiology centers, with acceptable complication rates. KEY WORDS: Ablation; Atrial fibrillation; Pulmonary vein isolation.