Effects of Pulmonary Vein Isolation for Atrial Fibrillation on Skin Sympathetic Nerve Activity in Association with Left Atrial Remodeling

Figures

• 

  Figure 1. Flowchart of the present study.

• 

  Figure 2. Representative skin sympathetic nerve activity (SKNA) waveforms. Among the waveforms obtained with neuECG, the top three are the raw SKNA waveform, the average SKNA (aSKNA) with burst threshold, and the heart rate (HR), respectively. The paroxysmal atrial fibrillation (PAF) group (A–D) demonstrated that SKNA amplitude, which was enhanced before ablation (A), attenuated after pulmonary vein isolation (PVI) (B). A mild increase in HR after PVI. Very low frequency (VLF) oscillations were dominant before PVI in the frequency distribution (C). Background high frequency (HF) oscillations became more pronounced after PVI (D). However, the persistent AF (PerAF) group (E–H) demonstrated decreased HR after PVI due to a return to sinus rhythm but with no difference in SKNA waveforms or frequency distribution.

• 

  Figure 3. Comparison of skin sympathetic nerve activity (SKNA) before pulmonary vein isolation (PVI) in paroxysmal atrial fibrillation (PAF) and persistent AF (PerAF). A comparison of SKNA before PVI between the PAF and PerAF groups is described. The solid lines in the figure represent the median and interquartile range. No differences were found in (A) non-burst amplitude and (B) burst amplitude. Frequency analysis revealed no differences in the very low frequency (VLFnu [normalized units {nu}]) between groups (C). The PAF group had significantly higher low frequency (LFnu) (D) and significantly lower high frequency (HFnu) (E). In addition, the LF/HF ratio also showed a higher level in the PAF group (F).

• 

  Figure 4. Changes in skin sympathetic nerve activity (SKNA) parameters before and after pulmonary vein isolation (PVI). A comparison of SKNA before and after PVI in paroxysmal atrial fibrillation (PAF) and persistent AF (PerAF) groups is shown, respectively. The dotted lines in the figure indicate the median value. No difference in non-burst amplitude was observed between the two groups (A), but a significant post-PVI reduction in burst amplitude was evident in the PAF group (B). No difference in very low frequency (VLFnu [normalized unit {nu}]) (C), but the low frequency (LFnu) decreased after PVI in the PAF group (D). High frequency (HFnu) was elevated, and the LF/HF ratio decreased in the PAF group (E,F), whereas the PerAF group demonstrated the opposite trend.

• 

  Figure 5. Comparison of the percentage changes in skin sympathetic nerve activity (SKNA) before and after pulmonary vein isolation (PVI). A comparison between paroxysmal atrial fibrillation (PAF) and persistent AF (PerAF) groups is described. The solid lines in the figure represent the median and interquartile range. No difference was found in (A) non-burst amplitude, but the PAF group demonstrated larger negative shifts from baseline in burst amplitude (B). Frequency analysis revealed no difference in the very low frequency (VLFnu [normalized unit {nu}]) between groups (C). The PAF group demonstrated significant negative shift in low frequency (LFnu) (D), positive shift in high frequency (HFnu) (E), and negative shift in LF/HF ratio (F).

• 

  Figure 6. Correlation between the percentage change in the LF/HF ratio and left atrial volume index (LAVI). (A) A positive correlation between the percentage change in the LF/HF ratio and LAVI in the paroxysmal atrial fibrillation (PAF) group. (B) Such a relationship was not evident in the persistent AF (PerAF) group.