ABSTRACT
BACKGROUND: Radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) changes cardiac autonomic nerve activity. However, the long-term effect of RFCA has not yet been evaluated when an open irrigation tip catheter (OITC) was used. Therefore, we hypothesized that AF ablation changes heart rate variability (HRV) that would be maintained over 1 year after OITC ablation and be associated with clinical recurrence of AF. METHODS AND RESULTS: We analyzed pre-RFCA HRV (HRVpre ), HRV at 3 months (HRV3mo ) and 1 year (HRV1yr ) after RFCA using 24-hour Holter monitoring after excluding arrhythmic events in 144 patients (70% male, 57 ± 10 years old, 83% paroxysmal AF) who underwent RFCA with OITC. After RFCA with OITC, the increase in mean heart rate and the reduction in HF or LF/HF were significant at HRV3mo (P < 0.001) and were maintained at HRV1yr (P < 0.001). During 20 ± 8 months of follow-up, 33 of 144 patients (23%) showed clinical recurrence of AF. Patients in the nonrecurrence group showed significant reductions of rMSSD and HF at HRV3mo and HRV1yr , but patients with clinical recurrence did not. In Cox regression analysis, a reduction in LF/HF (ΔLF/HF) ≥0.26 at HRV3mo was significantly associated with clinical recurrence of AF (hazard ratio 2.52, 95% CI 1.19-5.32, P = 0.015). CONCLUSION: In contrast to previous reports about long-term HRV recovery after AF ablation with a conventional catheter, change in cardiac autonomic nervous activity was maintained for 1 year after RFCA when an OITC was used. A reduction in ΔLF/HF ≥0.26 at HRV3mo was independently associated with clinical recurrence of AF after RFCA.
