Spinal cord stimulation suppresses atrial fibrillation by inhibiting autonomic remodeling.
BACKGROUND
Previous study has shown that spinal cord stimulation (SCS) may suppress atrial fibrillation (AF) inducibility, but the mechanism for this is elusive.


OBJECTIVE
The purpose of this study was to determine whether SCS could inhibit AF inducibility by suppressing autonomic remodeling in a canine model of rapid atrial pacing (RAP)-induced AF.


METHODS
Eighteen canines were randomly divided into an RAP group (n = 9) and an RAP+SCS group (n = 9). Effective refractory period (ERP), window of vulnerability (WOV), AF inducibility, autonomic neural function, and activity from the anterior right ganglionated plexus (ARGP) and left stellate ganglion (LSG) were measured at baseline, at 3 hours of RAP, and at 6 hours of RAP. Then, ARGP and LSG were excised for Western blot and messenger RNA analysis. In another 4 dogs (control group, which received sham RAP and sham SCS), tissues were also excised for analysis.


RESULTS
In the RAP group, RAP resulted in (1) a significant decrease in ERP and an increase in ERP dispersion, ΣWOV, and AF inducibility and (2) activation of ARGP and LSG versus baseline. In the RAP+SCS group, however, these changes were significantly attenuated by SCS. Compared with the control group, c-fos and nerve growth factor (NGF) were significantly up-regulated and small conductance calcium-activated potassium channel type 2 (SK2) was significantly down-regulated in the RAP group. In the RAP+SCS group, however, c-fos, NGF, and SK2 remained at a normal level compared with the control group.


CONCLUSIONS
SCS may suppress RAP-induced AF by inhibiting autonomic remodeling, and the underlying mechanism of the salutary effect of SCS might contribute to modulation of the expression of c-fos, NGF, and SK2.
Department of Cardiology, Renmin Hospital of Wuhan University, Cardiovascular Research Institute of Wuhan University, Wuhan, Hubei, China.
Songyun
S
Wang
Department of Cardiology, Renmin Hospital of Wuhan University, Cardiovascular Research Institute of Wuhan University, Wuhan, Hubei, China.
Xiaoya
X
Zhou
Department of Cardiology, Renmin Hospital of Wuhan University, Cardiovascular Research Institute of Wuhan University, Wuhan, Hubei, China.
Bing
B
Huang
Department of Cardiology, Renmin Hospital of Wuhan University, Cardiovascular Research Institute of Wuhan University, Wuhan, Hubei, China.
Zhuo
Z
Wang
Department of Cardiology, Renmin Hospital of Wuhan University, Cardiovascular Research Institute of Wuhan University, Wuhan, Hubei, China.
Liping
L
Zhou
Department of Cardiology, the Second Xiangya Hospital of Central South University, Changsha, Hunan, China.
Mingxian
M
Chen
Department of Cardiology, Renmin Hospital of Wuhan University, Cardiovascular Research Institute of Wuhan University, Wuhan, Hubei, China,. Electronic address: whuyulilei@163.com.
Lilei
L
Yu
Department of Cardiology, Renmin Hospital of Wuhan University, Cardiovascular Research Institute of Wuhan University, Wuhan, Hubei, China,. Electronic address: whujianghong@163.com.
Hong
H
Jiang
D000818:Animals; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control; D064752:Atrial Remodeling / Q000502:physiology; D002304:Cardiac Pacing, Artificial / Q000379:methods; D004195:Disease Models, Animal; D004285:Dogs; D015536:Down-Regulation / Q000502:physiology; D004562:Electrocardiography / Q000379:methods; D006325:Heart Atria / Q000378:metabolism / Q000503:physiopathology; D006329:Heart Conduction System / Q000378:metabolism / Q000503:physiopathology; D020932:Nerve Growth Factor / Q000378:metabolism; D051640:Small-Conductance Calcium-Activated Potassium Channels / Q000378:metabolism; D062187:Spinal Cord Stimulation / Q000379:methods*; D013233:Stellate Ganglion / Q000503:physiopathology*; D015854:Up-Regulation / Q000502:physiology
C496897:KCNN2 protein, human; D051640:Small-Conductance Calcium-Activated Potassium Channels; D020932:Nerve Growth Factor
Atrial fibrillation; Autonomic remodeling; Spinal cord stimulation