Background It has been reported that radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) modulates autonomic nerve activity and changes the pattern of heart rate variability (HRV). We hypothesized that ablation duration or ablation technique may affect HRV and clinical outcome.
Methods We performed 3rd month 24-hour Holter recording in 157 patients who underwent AF ablation (paroxysmal AF (PAF), n=109; persistent AF (PeAF), n=48). The heart rate and HRV were analyzed in highly selected patients who were not taking anti-arrhythmic drugs or β-blocker maintaining sinus rhythm (n=119). Circumferential pulmonary vein isolation (CPVI) was done in all the patients, and additional roof line (RL) or posterior box lesion (PostBox) were randomly assigned in PAF, and CPVI+PostBox with or without additional anterior linear ablation (AntL) were performed in PeAF; 37 CPVI only, 27 CPVI+RL, 36 CPVI+PostBox, and 19 CPVI+PostBox+AntL.
Results 1. There were no significant differences in heart rate, HRV parameters, or clinical outcome between patients who underwent longer duration of RF energy delivery (≥5400 sec, n=48) and shorter duration of RF energy delivery (n=71). 2. HRV patterns were not significantly different among the patients who underwent CPVI, CPVI+RL, CPVI+PostBox, and CPVI+PostBox+AntL. 3. HF domain (17.6 ± 17.2 ms2 vs. 6.8 ± 4.5 ms2, p<0.001) and number of atrial premature beats (APCs; 1747 ± 3178 vs. 434 ± 1025, p=0.004) were significantly higher in patients who recurred 3 months after RFCA (7 %) than those who were remaining in sinus rhythm during 8 ± 3 months follow-up. The percent of APC (>1%) in 3rd month Holter was an independent predictor of clinical recurrence of AF after RFCA (OR 4.9, CI 1.14 ~ 21.5, p=0.033).
Conclusion HRV pattern were not different 3 months after AF ablation regardless of the duration of RF energy delivery or additional linear ablation site after CPVI in patients with AF. But, the frequency of APCs after 3 months was an independent risk factor for AF recurrence. Although post-RFCA parasympathetic activity might be related with clinical recurrence of AF, CPVI is enough for autonomic modulation in left atrium.
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