scholarly journals Enhanced atrial internal-external neural remodeling facilitates atrial fibrillation in the chronic obstructive sleep apnea model

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247308
Author(s):  
Jiasuoer Xiaokereti ◽  
Yan-Kai Guo ◽  
Zhen-Yu Dong ◽  
Mei Ma ◽  
Yan-Mei Lu ◽  
...  

Objective Autonomic imbalance plays a crucial role in obstructive sleep apnea (OSA) associated atrial fibrillation (AF). Here, we investigated the potential neural mechanism of AF induced by OSA. Methods Ten dogs were divided into control group (n = 5) and OSA group (n = 5). The chronic OSA model was established by repeat apnea-ventilation cycles for 4 hours a day for 12 weeks. During the process of model establishment, arterial blood gases, atrial effective refractory period (AERP), AF inducibility, normalized low-frequency power (LFnu), normalized high-frequency power (HFnu), and LFnu/ HFnu were evaluated at baseline, 4th week, 8th week, and 12th week. Nerve activities of left stellate ganglion (LSG) and left vagal nerve(LVN) were recorded. Tyrosine hydroxylase(TH), choline acetyltransferase(CHAT), PGP9.5, nerve growth factor(NGF), and c-Fos were detected in the left atrium, LSG, and LVN by immunohistochemistry and western blot. Moreover, high-frequency stimulations of LSG and LVN were conducted to observe the AF inducibility. Results Compared with the control group, the OSA group showed significantly enhanced neural activity of the LSG, increased AF inducibility, and shortened AERP. LFnu and LFnu/HFnu were markedly increased in the OSA group, while no significant difference in HFnu was observed. TH-positive and PGP9.5-positive nerve densities were significantly increased in the LSG and left atrium. Additionally, the protein levels of NGF, c-Fos, and PGP9.5 were upregulated both in the LSG and left atrium. AF inducibility was markedly increased under LSG stimulation without a stimulus threshold change in the OSA group. Conclusions OSA significantly enhanced LSG and left atrial neural remodeling, and hyperactivity of LSG may accelerate left atrial neural remodeling to increase AF inducibility.

Biomedicines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1463
Author(s):  
Yung-Lung Chen ◽  
Yung-Che Chen ◽  
Ya-Ting Chang ◽  
Hui-Ting Wang ◽  
Wen-Hao Liu ◽  
...  

Obstructive sleep apnea syndrome (OSAS) is an important risk factor for atrial fibrillation (AF). GJA1 gene encoding connexin43, a major protein in cardiac gap junctions, plays a crucial role in the synchronized contraction of the heart and in cardiac arrhythmia. However, little is known regarding the role of GJA1 expression in the incidence of AF in patients with OSAS. All prospectively enrolled OSAS patients underwent polysomnography, electrocardiography, a 24-hour Holter test, and echocardiography. Moderate-to-severe OSAS was defined as an apnea-hypopnea index (AHI) ≥ 15. Exosomes were purified from the plasma of all OSAS patients and incubated in HL-1 cells to investigate the effect of exosomes from patients with and without AF on GJA1 expression. A total of 129 patients were recruited for this study; 26 were excluded due to an AHI < 15. Of the 103 enrolled patients, 21 had AF, and 82 did not. Multivariate analysis showed diabetes mellitus, lower sleep efficiency, lower left ventricular ejection fraction, and larger left atrial (LA) size were independent predictors of AF occurrence in OSAS patients. The area under the receiver operating characteristic curve for LA with a size ≥ 38.5 mm for predicting AF occurrence in OSAS patients was 0.795 (95% confidence interval [0.666, 0.925]); p < 0.001). GJA1 expression in HL-1 cells incubated with exosomes from OSAS patients with AF was lower than that with exosomes from patients without AF after controlling for age and sex and was negatively correlated with the AHI and oxygen desaturation index (ODI), especially during the non-rapid eye movement period (NREM) of OSAS patients with AF (all p < 0.05). LA size was an independent predictor of AF occurrence in OSAS patients. The AHI and ODI in the NREM period of OSAS patients with AF were negatively correlated with GJA1 expression in HL-1 cells, which offers a hint that GJA1 may play a crucial role in the development of AF in patients with OSAS.


2011 ◽  
Vol 27 (Supplement) ◽  
pp. OP36_3
Author(s):  
Mitsunobu Enomoto ◽  
Katsuaki Yokoyama ◽  
Yasuhito Kubochi ◽  
Masakazu Komoriya ◽  
Hidehito Takase ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Ling Zhang ◽  
Yankai Guo ◽  
Jiasuoer Xiaokereti ◽  
Guiqiu Cao ◽  
Hongliang Li ◽  
...  

Background: Previous studies have reported that right pulmonary artery ganglionated plexi (GP) ablation could suppress the onset of atrial fibrillation (AF) associated with obstructive sleep apnea (OSA) within 1 h.Objective: This study aimed to investigate the effect of superior left GP (SLGP) ablation on AF in a chronic OSA canine model.Methods and Results: Fifteen beagles were randomly divided into three groups: control group (CTRL), OSA group (OSA), and OSA + GP ablation group (OSA + GP). All animals were intubated under general anesthesia, and ventilation-apnea events were subsequently repeated 4 h/day and 6 days/week for 12 weeks to establish a chronic OSA model. SLGP were ablated at the end of 8 weeks. SLGP ablation could attenuate the atrial effective refractory period (ERP) reduction and decrease ERP dispersion, the window of vulnerability, and AF inducibility. In addition, chronic OSA leads to left atrial (LA) enlargement, decreased left ventricular (LV) ejection fraction, glycogen deposition, increased necrosis, and myocardial fibrosis. SLGP ablation reduced the LA size and ameliorated LV dysfunction, while myocardial fibrosis could not be reversed. Additionally, SLGP ablation mainly reduced sympathovagal hyperactivity and post-apnea blood pressure and heart rate increases and decreased the expression of neural growth factor (NGF), tyrosine hydroxylase (TH), and choline acetyltransferase (CHAT) in the LA and SLGP. After SLGP ablation, the nucleotide-binding oligomerization domain (NOD)-like receptor signaling pathway, cholesterol metabolism pathway, and ferroptosis pathway were notably downregulated compared with OSA.Conclusions: SLGP ablation suppressed AF in a chronic OSA model by sympathovagal hyperactivity inhibition. However, there were no significant changes in myocardial fibrosis.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Jie Cai ◽  
Min Tang ◽  
Hao Liu ◽  
Shiao Ding ◽  
Rongxin Lu ◽  
...  

Objective. The purpose is to observe the effects and neural mechanism of cutting upper thoracic sympathetic trunk (TST) on the ventricular rate (VR) during persistent atrial fibrillation (AF). Methods. Twelve beagle dogs were halving to the control group and experimental group, 6 dogs for each group. Both groups were performed with left atrial rapid pacing (600 beats/min) to induce sustained AF. The experimental group underwent cutting upper TST  after a sustained AF model was established, while the control group received thoracotomy without cutting TST. Bilateral stellate ganglion (SG) and left atrial myocardium were harvested for tyrosine-hydroxylase (TH) immunohistochemical staining. Results. After cutting upper TST for 30 minutes, the average VR was 121.5 ± 8.7 bpm (95% CI, 114.8 to 128.0) in the experimental group, which was significantly slower than that of the control group (144.5 ± 4.2 bpm (95% CI, 141.5 to 148.0)) ( P < 0.001 ). After cutting upper TST for 1 month, the average VR of the experimental group (106.5 ± 4.9 bpm (95% CI, 102.0 to 110.0)) was also significantly slower versus that of the control group (139.2 ± 5.6 bpm (95% CI, 135.0 to 143.8)) ( P < 0.001 ). Compared with the control group, both left stellate ganglion (LSG) and right stellate ganglion (RSG) of the experimental group caused neural remodeling characterized by decreased ganglionic cell density and reduced TH staining. TH-positive component was significantly decreased in the left atrium of the experimental group compared with the control group. Conclusions. Cutting upper TST could reduce fast VR during persistent AF. Cutting upper TST induced bilateral SG neural remodeling and reduced sympathetic nerve density in the left atrium, which could contribute to the underlying mechanism of VR control during AF.


OTO Open ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 2473974X2198959
Author(s):  
Ahmed Yassin Bahgat

Objective Plasma is formed by creating a high-density energy field within an electrically conductive fluid such as saline. Sometimes ablated bits of tissue get stuck between the electrodes of the wand, obstructing the suction channel. The purpose of this study is to investigate the effect of cooling the irrigating saline during ablation of the hypertrophied tongue base in patients with obstructive sleep apnea. Study Design Prospective randomized controlled trial. Setting An otorhinolaryngology department in Main University hospitals. Methods Sixty adult patients with obstructive sleep apnea and tongue base hypertrophy underwent tongue base ablation surgery. Patients were randomly divided into 2 groups of 30 patients each: cooled saline and room temperature saline. The Coblation wand used was the EVac 70 Xtra HP (Smith & Nephew). Results In this study, a significant difference in operative time (mean ± SD) was seen between groups: 21.2 ± 5.5 minutes in the cold group and 47 ± 9.5 minutes in the control group ( P = .001). The wands in the cold group did not obstruct, while all the wands in the control group were obstructed by tissue clogs with variable degrees, hence wasting more time to clean the wands’ tips. Conclusion Cooling the irrigating saline overcame the problem of wand clogs, and the wand tip did not occlude at all during the procedures, thus saving time lost in wand cleaning and demonstrating a faster and safer surgical procedure. Further studies are needed to identify the hemostatic effect of the cooled saline over the regular one.


2021 ◽  
pp. 112067212110065
Author(s):  
Murat Serkan Songur ◽  
Yavuz Selim İntepe ◽  
Seray Aslan Bayhan ◽  
Hasan Ali Bayhan ◽  
Ender Şahin ◽  
...  

Purpose: In the present study we evaluate the corneal endothelium using specular microscopy in patients with obstructive sleep apnea syndrome (OSAS). Methods: The study included a total of 100 patients including 35 patients with mild OSAS, 34 patients with moderate OSAS and 31 patients with severe OSAS, and the right eyes of 30 patients as a control group. Patients were examined to exclude the possibility of ocular diseases. Cellular density in the cornea epithelium (cell/mm2), corneal thickness (µ), percentage of hexagonal cells (%) and the coefficient of variation were evaluated using a specular microscope. Results: Corneal thickness was significantly decreased in all OSAS groups when compared to the control group ( p = 0.002), while no significant difference was identified among the OSAS groups. The corneal endothelial cell density, percentage of hexagonal cells and coefficient of variation were significantly different between the OSAS groups and the control group ( p < 0.001). Conclusion: More significant impairments were noted in the corneal endothelium of the patients in the OSAS group than in the control group, and specular microscopy is in valuable in the follow-up and treatment of such patients.


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