Cardiovascular Research Advance Access originally published online on June 11, 2009
Cardiovascular Research 2009 84(2):245-252; doi:10.1093/cvr/cvp194
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Autonomic mechanism for initiation of rapid firing from atria and pulmonary veins: evidence by ablation of ganglionated plexi
1 Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
2 Heart Rhythm Institute in the University of Oklahoma Health Sciences Center, 1200 Everett Drive, Room ET6E103, Oklahoma, OK 73104, USA
3 Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, China
4 Department of Cardiac Electrophysiology, People's Hospital, Peking University, Beijing, China
* Corresponding author. Tel: +1 405 271 9696; fax: +1 405 271 7455. E-mail address: sunny-po{at}ouhsc.edu
Aims: Previous studies showed that autonomic activation by high-frequency electrical stimulation (HFS) during myocardial refractoriness evokes rapid firing from pulmonary vein (PV) and atria, both in vitro and in vivo. This study sought to investigate the autonomic mechanism underlying the rapid firings at various sites by systematic ablation of multiple ganglionated plexi (GP).
Methods and results: In 43 mongrel dogs, rapid firing-mediated atrial fibrillation (AF) was induced by local HFS (200 Hz, impulse duration 0.1 ms, train duration 40 ms) to the PVs and atria during myocardial refractoriness. The main GP in the atrial fat pads or the ganglia along the ligament of Marshall (LOM) were then ablated. Ablation of the anterior right GP and inferior right GP significantly increased the AF threshold by HFS at the right atrium and PVs. The AF threshold at left atrium and PVs was significantly increased by ablation of the superior left GP and inferior left GP, and was further increased by ablation of the LOM. Ablation of left- or right-sided GP on the atria had a significant effect on contralateral PVs and atrium. Administration of esmolol (1 mg/kg) or atropine (1 mg) significantly increased AF threshold at all sites.
Conclusion: HFS applied to local atrial and PV sites initiated rapid firing via activation of the interactive autonomic network in the heart. GP in either left side or right side contributes to the rapid firings and AF originating from ipsolateral and contralateral PVs and atrium. Autonomic denervation suppresses or eliminates those rapid firings.
KEYWORDS Atrial fibrillation; Ganglionated plexus; Autonomic nervous system
Time for primary review: 19 days