Skin sympathetic nerve activity and ventricular rate control during atrial fibrillation

Abstract Background The relationship between ventricular rate (VR) during atrial fibrillation (AF) and the skin sympathetic nerve activity (SKNA) remain unclear. Objective To test the hypothesis that SKNA bursts accelerate VR during AF. Methods We simultaneously recorded electrocardiogram and SKNA from 8 patients (median age 66.0 years [interquartile range (IQR) 59.0 – 77.0], 4 males) with 30 paroxysmal AF episodes (all >10 min long) and 12 patients (73.0 years [IQR 60.5 – 80.0], 6 males) with persistent AF. The average voltage of SKNA (aSKNA, μV) during AF was analyzed in one-min windows and binned, showing two Gaussian distributions. We used the mean + 3 standard deviation as the threshold that separates burst from baseline (non-burst) SKNA. All 1-min aSKNA above threshold were detected and the area between aSKNA and baseline of every 1-min was calculated and added together as burst area. Results The VR was higher during SKNA bursts than during non-burst period (103 bpm [IQR 83 – 113] vs. 88 bpm [IQR 76 – 101], respectively, p = 0.003). In the highest quartile of the burst area during persistent AF, scatter plot of maximal aSKNA and VR during each SKNA burst shows higher aSKNA and VR. Overall estimates of correlation coefficient between maximal VR and aSKNA during bursts shows a positive correlation in the highest quartile of the burst area (0.64 [95% CI 0.54 – 0.74], p Conclusion SKNA bursts are associated with VR acceleration. These SKNA bursts may be new therapeutic targets for rate control during AF.