title: Low-level vagosympathetic trunk stimulation inhibits atrial fibrillation in a rabbit model of obstructive sleep apnea.
abstract: BACKGROUND
  Atrial fibrillation (AF) is highly associated with obstructive sleep apnea (OSA) in which AF is triggered by hyperactivity of the cardiac autonomic nervous system. Previous studies showed that low-level vagosympathetic trunk stimulation (LLVS), at voltages not slowing sinus rate or AV conduction, inhibits AF by suppressing the cardiac autonomic nervous system.
  
  
  OBJECTIVE
  The purpose of this study was to investigate whether LLVS delivered at the right vagosympathetic trunk suppresses AF in a rabbit model of OSA.
  
  
  METHODS
  Eleven rabbits received a tracheostomy under general anesthesia. The endotracheal tube was clamped at end expiration for 1 minute to simulate OSA. Over a period of 4 hours, OSA was delivered every 6 minutes. Effective refractory period (ERP), blood pressure, intraesophageal pressure, and blood gases (O2, CO2, pH) were measured before and after each episode of OSA. AF duration and ERP were measured by programmed stimulation. Group 1 rabbits (n = 6) received LLVS (50% below that which slowed the sinus rate) in the first 3 hours. Group 2 rabbits (n = 5) only received OSA.
  
  
  RESULTS
  Group 1 ERP began to lengthen progressively from the second hour compared to group 2. AF duration increased in the first hour for both groups but began to shorten progressively after the first hour in group 1 rabbits. Blood pH, O2 or CO2 level, intraesophageal pressure, and hypertensive response during OSA were not different between the 2 groups.
  
  
  CONCLUSIONS
  LLVS is capable of suppressing ERP shortening and AF induced by OSA. LLVS may serve as a new therapeutic approach to treat OSA-induced AF.
authors.affiliation: Department of Cardiology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Gao
authors.affiliation: Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Scherlag
authors.affiliation: Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Bing
authors.initials: B
authors.lastname: Huang
authors.affiliation: Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Stavros
authors.initials: S
authors.lastname: Stavrakis
authors.affiliation: Department of Cardiovascular Diseases, the 6th People's Hospital, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Yue-Mei
authors.initials: YM
authors.lastname: Hou
authors.affiliation: Department of Cardiology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, China.
authors.forename: Yinglong
authors.initials: Y
authors.lastname: Hou
authors.affiliation: Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma. Electronic address: sunny-po@ouhsc.edu.
authors.forename: Sunny S
authors.initials: SS
authors.lastname: Po
mesh_terms: D000818:Animals; D001281:Atrial Fibrillation / Q000209:etiology / Q000503:physiopathology; D001341:Autonomic Nervous System / Q000503:physiopathology*; D022062:Electrophysiologic Techniques, Cardiac; D006325:Heart Atria / Q000294:innervation / Q000503:physiopathology; D006329:Heart Conduction System / Q000503:physiopathology; D023421:Models, Animal; D011817:Rabbits; D020181:Sleep Apnea, Obstructive / Q000150:complications*; D055536:Vagus Nerve Stimulation / Q000379:methods*
keywords: Atrial fibrillation; Autonomic nervous system; Obstructive sleep apnea