Mei Gao1, Ling Zhang2, Benjamin J Scherlag3, Bing Huang3, Stavros Stavrakis3, Yue-Mei Hou4, Yinglong Hou1, Sunny S Po5. 1. Department of Cardiology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, China. 2. Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, China. 3. Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma. 4. Department of Cardiovascular Diseases, the 6th People's Hospital, Shanghai Jiaotong University, Shanghai, China. 5. Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma. Electronic address: sunny-po@ouhsc.edu.
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. CONCLUSION: 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.
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. CONCLUSION: 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: Bettina Kronsteiner; Lydia M Zopf; Patrick Heimel; Gunpreet Oberoi; Anne M Kramer; Paul Slezak; Wolfgang J Weninger; Bruno K Podesser; Attila Kiss; Francesco Moscato Journal: Front Cell Dev Biol Date: 2022-09-12