Atrial autonomic innervation remodelling and atrial fibrillation inducibility after epicardial ganglionic plexi ablation.
OBJECTIVE
The effects of ganglionated plexi (GP) ablation on atrial fibrillation (AF) inducibility and atrial autonomic innervation remodelling have not been elucidated.


RESULTS
Thirteen dogs were randomly divided into sham-operated group and GP ablation group. All animals underwent a right thoracotomy at the fourth intercostal space. Atrial fibrillation inducibility was assessed by burst rapid pacing at right atrium (RA). After anterior right GP and inferior right GP ablation, AF inducibility was assessed in the GP ablation group. The animals were allowed to recover for 8 weeks, after which, AF was measured again. The levels of atrial natriuretic peptide (ANP) in blood and atrial tissues were examined by radioimmunoassay. Immunocytochemical staining of cardiac nerves was performed in tissues from the dogs. Atrial fibrillation was induced easily in the GP ablation group after 8 weeks although AF was not observed in the sham-operated group, and after instant GP ablation. Compared with that in the sham-operated group, the levels of ANP in the blood and RA increased significantly 8 weeks after GP ablation (111.4 +/- 18.2 vs. 175.1 +/- 25.9; 184.9 +/- 36.3 vs. 299.1 +/- 32.5; P < 0.05). In the GP ablation group, the density of growth-associated protein 43-positive, tyrosine hydroxylase-positive, and choline acetyltransferase-positive nerves in the RA was 821 +/- 752, 481 +/- 627, and 629 +/- 644 per mm(2), respectively, which was significantly (P < 0.01) lower than the nerve density in sham-operated tissues (2590 +/- 841, 1752 +/- 605, and 3147 +/- 886 per mm(2), respectively).


CONCLUSIONS
Atrial autonomic innervations remodelling may be the mechanism of induced AF after GP ablation.
Zhao
Qing-Yan
QY
Cardiovascular Research Institute of Wuhan University, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang, Wuhan City 430060, People's Republic of China.
Huang
He
H
Zhang
Shu-Di
SD
Tang
Yan-Hong
YH
Wang
Xi
X
Zhang
Yu-Guo
YG
Salim
Mohamed
M
Okello
Emmy
E
Deng
Hong-Ping
HP
Yu
Sheng-Bo
SB
Huang
Cong-Xin
CX
D000818:Animals; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*; D009320:Atrial Natriuretic Factor / Q000097:blood; D017776:Autonomic Pathways / Q000502:physiology / Q000601:surgery; D002304:Cardiac Pacing, Artificial; D002306:Cardiac Volume; D017115:Catheter Ablation; D002799:Cholinergic Fibers / Q000378:metabolism; D003714:Denervation / Q000379:methods; D004195:Disease Models, Animal; D004285:Dogs; D004562:Electrocardiography; D005260:Female; D019922:GAP-43 Protein / Q000378:metabolism; D005725:Ganglia, Autonomic / Q000502:physiology* / Q000601:surgery; D006321:Heart / Q000294:innervation* / Q000503:physiopathology; D006325:Heart Atria / Q000294:innervation / Q000503:physiopathology; D007150:Immunohistochemistry; D008297:Male; D011863:Radioimmunoassay; D012008:Recurrence
D019922:GAP-43 Protein; D009320:Atrial Natriuretic Factor