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Gao P, Gao X, Xie B, Tse G, Liu T. Aging and atrial fibrillation: A vicious circle. Int J Cardiol 2024; 395:131445. [PMID: 37848123 DOI: 10.1016/j.ijcard.2023.131445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 09/17/2023] [Accepted: 10/12/2023] [Indexed: 10/19/2023]
Abstract
Atrial fibrillation (AF) is the commonest sustained cardiac arrhythmia observed in clinical practice. Its prevalence increases dramatically with advancing age. This review article discusses the recent advances in studies investigating the relationship between aging and AF and the possible underlying mechanisms.
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Affiliation(s)
- Pan Gao
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Xinyi Gao
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Bingxin Xie
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Gary Tse
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China; School of Nursing and Health Studies, Hong Kong Metropolitan University, Hong Kong, China
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China.
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Cheng Y, Deng H, Ling Y, Lin W, Liang Z, Chen Y, Fang X, Liao H, Liu Y, Wei H, Liu F, Jiang J, Wu S, Xue Y, Wu Z. Higher Cumulative Blood Pressure in Midlife Predicts an Increased Risk of Atrial Fibrillation: Evidence From the Atherosclerosis Risk in Communities Study. J Am Heart Assoc 2023; 12:e030409. [PMID: 38084710 PMCID: PMC10863776 DOI: 10.1161/jaha.123.030409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 11/14/2023] [Indexed: 12/20/2023]
Abstract
BACKGROUND Elevated blood pressure (BP) is reportedly associated with an increased risk of atrial fibrillation (AF). However, the association between cumulative BP exposure in midlife and incident AF in mid-to-late life remains unclear. METHODS AND RESULTS Participants enrolled in the ARIC (Atherosclerosis Risk in Communities) study with 4 consecutive BP measurements and no prevalent AF at baseline were included. Cumulative BP was calculated as the area under the curve from visit 1 to visit 4. Incident AF was identified by study visit ECGs, hospital discharge codes, or death certificates. A total of 9892 participants were included (44.6% men and mean age 62.9±5.7 years at visit 4) with 1550 (15.7%) individuals who developed new-onset AF during an average follow-up of 15.4 years. The incidence rates of AF per 1000 person-years across the 4 quartiles of cumulative systolic BP were 7.9, 9.2, 12.5, and 16.9, respectively. After multivariable adjustment, the hazard ratios for incident AF among participants in the highest quartile of cumulative systolic BP, pulse pressure, and mean arterial pressure were 1.48 (95% CI, 1.27-1.72), 1.81 (95% CI, 1.53-2.13), and 1.22 (95% CI, 1.05-1.41), respectively, compared with those in the lowest quartile. The addition of cumulative systolic BP or pulse pressure slightly improved the ability to predict new-onset AF. CONCLUSIONS Higher exposure to cumulative systolic BP, pulse pressure, and mean arterial pressure was significantly associated with increased risk of incident AF.
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Affiliation(s)
- Yun‐Jiu Cheng
- Department of Guangdong Cardiovascular Institute, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouChina
- The Second School of Clinical MedicineSouthern Medical UniversityGuangzhouChina
| | - Hai Deng
- Department of Guangdong Cardiovascular Institute, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouChina
| | - Yun Ling
- Department of Cardiovascular SurgeryShanghai East Hospital Affiliated to Tongji University School of MedicineShanghaiChina
| | - Wei‐Dong Lin
- Department of Guangdong Cardiovascular Institute, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouChina
| | - Zhuomin Liang
- Department of Cardiology, The First Affiliated HospitalSun Yat‐sen UniversityGuangzhouChina
- NHC Key Laboratory of Assisted Circulation and Vascular Diseases (Sun Yat‐sen University)GuangzhouChina
| | - Yili Chen
- Department of Cardiology, The First Affiliated HospitalSun Yat‐sen UniversityGuangzhouChina
- NHC Key Laboratory of Assisted Circulation and Vascular Diseases (Sun Yat‐sen University)GuangzhouChina
| | - Xian‐Hong Fang
- Department of Guangdong Cardiovascular Institute, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouChina
| | - Hong‐Tao Liao
- Department of Guangdong Cardiovascular Institute, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouChina
| | - Yang Liu
- Department of Guangdong Cardiovascular Institute, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouChina
| | - Hui‐Qiang Wei
- Department of Guangdong Cardiovascular Institute, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouChina
| | - Fang‐Zhou Liu
- Department of Guangdong Cardiovascular Institute, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouChina
| | - Jun‐Rong Jiang
- Department of Guangdong Cardiovascular Institute, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouChina
| | - Shu‐Lin Wu
- Department of Guangdong Cardiovascular Institute, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouChina
| | - Yu‐Mei Xue
- Department of Guangdong Cardiovascular Institute, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouChina
| | - Zexuan Wu
- Department of Cardiology, The First Affiliated HospitalSun Yat‐sen UniversityGuangzhouChina
- NHC Key Laboratory of Assisted Circulation and Vascular Diseases (Sun Yat‐sen University)GuangzhouChina
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Shu H, Cheng J, Li N, Zhang Z, Nie J, Peng Y, Wang Y, Wang DW, Zhou N. Obesity and atrial fibrillation: a narrative review from arrhythmogenic mechanisms to clinical significance. Cardiovasc Diabetol 2023; 22:192. [PMID: 37516824 PMCID: PMC10387211 DOI: 10.1186/s12933-023-01913-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 07/02/2023] [Indexed: 07/31/2023] Open
Abstract
The prevalence of obesity and atrial fibrillation (AF), which are inextricably linked, is rapidly increasing worldwide. Obesity rates are higher among patients with AF than healthy individuals. Some epidemiological data indicated that obese patients were more likely to develop AF, but others reported no significant correlation. Obesity-related hypertension, diabetes, and obstructive sleep apnea are all associated with AF. Additionally, increased epicardial fat, systemic inflammation, and oxidative stress caused by obesity can induce atrial enlargement, inflammatory activation, local myocardial fibrosis, and electrical conduction abnormalities, all of which led to AF and promoted its persistence. Weight loss reduced the risk and reversed natural progression of AF, which may be due to its anti-fibrosis and inflammation effect. However, fluctuations in weight offset the benefits of weight loss. Therefore, the importance of steady weight loss urges clinicians to incorporate weight management interventions in the treatment of patients with AF. In this review, we discuss the epidemiology of obesity and AF, summarize the mechanisms by which obesity triggers AF, and explain how weight loss improves the prognosis of AF.
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Affiliation(s)
- Hongyang Shu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095# Jiefang Ave, Wuhan, 430000, China
- Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, 430000, China
| | - Jia Cheng
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095# Jiefang Ave, Wuhan, 430000, China
- Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, 430000, China
| | - Na Li
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095# Jiefang Ave, Wuhan, 430000, China
- Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, 430000, China
| | - Zixuan Zhang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095# Jiefang Ave, Wuhan, 430000, China
- Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, 430000, China
| | - Jiali Nie
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095# Jiefang Ave, Wuhan, 430000, China
- Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, 430000, China
| | - Yizhong Peng
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430000, China
| | - Yan Wang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095# Jiefang Ave, Wuhan, 430000, China
- Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, 430000, China
| | - Dao Wen Wang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095# Jiefang Ave, Wuhan, 430000, China
- Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, 430000, China
| | - Ning Zhou
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095# Jiefang Ave, Wuhan, 430000, China.
- Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, 430000, China.
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Anti-inflammatory effects of endothelin receptor blockade in left atrial tissue of spontaneously hypertensive rats. IJC HEART & VASCULATURE 2022; 42:101088. [PMID: 35879971 PMCID: PMC9307454 DOI: 10.1016/j.ijcha.2022.101088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 07/08/2022] [Accepted: 07/10/2022] [Indexed: 11/22/2022]
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Silencing of TLR4 Inhibits Atrial Fibrosis and Susceptibility to Atrial Fibrillation via Downregulation of NLRP3-TGF-β in Spontaneously Hypertensive Rats. DISEASE MARKERS 2022; 2022:2466150. [PMID: 35860690 PMCID: PMC9293556 DOI: 10.1155/2022/2466150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 06/04/2022] [Accepted: 06/23/2022] [Indexed: 12/18/2022]
Abstract
Introduction. This study was aimed at exploring whether silencing of TLR4 could inhibit atrial fibrosis and susceptibility to atrial fibrillation (AF) by regulating NLRP3-TGF-β in hypertensive rats. Methods. Spontaneously hypertensive rats (SHRs) were transfected with either a virus containing TLR4-shRNA to downregulate TLR4 or an empty virus (vehicle) at the age of 14 weeks. Fibrosis of left atrium and susceptibility to AF were detected, and expression of NLRP3-TGF-β in left atrial tissue at 22 weeks of age was measured. Primary cardiac fibroblasts were transfected with TLR4-shRNA or scrambled vehicle and stimulated with angiotensin (Ang) II. Proliferation of cardiac fibroblasts and expression of NLRP3-TGF-β were detected. Results. Silencing of TLR4 reduced left atrial fibrosis and susceptibility to AF in SHRs and downregulated expression of NLRP3, TGF-β, and collagen I. In vitro, TLR4 silencing reduced proliferation of cardiac fibroblasts induced by Ang II as well as expression of NLRP3, TGF-β, and collagen I. Conclusion. Silencing of TLR4 can downregulate NLRP3-TGF-β to reduce atrial fibrosis and susceptibility to AF in SHRs.
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Zubair Khan M, Gupta A, Hodge J, Patel K, Patel K, Zarak MS, Franklin S, Patel H, Jesani S, Savani S, Shah V, Figueredo VM, Cavale AR, Kutalek S. Clinical outcomes of atrial fibrillation with hyperthyroidism. J Arrhythm 2021; 37:942-948. [PMID: 34386120 PMCID: PMC8339080 DOI: 10.1002/joa3.12550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 03/23/2021] [Accepted: 04/18/2021] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Atrial fibrillation (Afib) is a common cardiac manifestation of hyperthyroidism. The data regarding outcomes of Afib with and without hyperthyroidism are lacking. HYPOTHESIS We hypothesized that patients with Afib and hyperthyroidism have better clinical outcomes, compared with Afib patients without hyperthyroidism. METHODS We queried the National Inpatient Sample database for years 2015-2017 using Validated ICD-10-CM codes for Afib and hyperthyroidism. Patients were separated into two groups, Afib with hyperthyroidism and without hyperthyroidism. RESULTS The study was conducted with 68 095 278 patients. A total of 9 727 295 Afib patients were identified, 90 635 (0.9%) had hyperthyroidism. The prevalence of hyperthyroidism was higher in patients with Afib (0.9% vs 0.4%, P < .001), compared with patients without Afib. Using multivariate regression analysis adjusting for various confounding factors, the odds ratio of Afib with hyperthyroidism was 2.08 (CI 2.07-2.10; P < .0001). Afib patients with hyperthyroidism were younger (71 vs 75 years, P < .0001) and more likely to be female (64% vs 47%; P < .0001) as compared with Afib patients without hyperthyroidism. Afib patients with hyperthyroidism had lower prevalence of CAD (36% vs 44%, P < .0001), cardiomyopathy (24.1% vs 25.9%, P < .0001), valvular disease (6.9% vs 7.4%, P < .0001), hypertension (60.7% vs 64.4%, P < .0001), diabetes mellitus (29% vs 32%, P < .0001) and obstructive sleep apnea (10.5% vs 12.2%, P < .0001). Afib with hyperthyroidism had lower hospitalization cost ($14 968 ± 21 871 vs $15 955 ± 22 233, P < .0001), shorter mean length of stay (5.7 ± 6.6 vs 5.9 ± 6.6 days, P < .0001) and lower in-hospital mortality (3.3% vs 4.8%, P < .0001. The disposition to home was higher in Afib with hyperthyroidism patients (51% vs 42; P < .0001). CONCLUSION Hyperthyroidism is associated with Afib in both univariate and multivariate analysis. Afib patients with hyperthyroidism have better clinical outcomes, compared with Afib patients without hyperthyroidism.
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Affiliation(s)
| | - Ashwani Gupta
- Division of CardiologySt. Mary Medical CenterLanghornePAUSA
| | - Jordesha Hodge
- Department of Internal MedicineSt. Mary Medical CenterLanghornePAUSA
| | - Kirtenkumar Patel
- Department of CardiologyNorth Shore University HospitalManhassetNYUSA
| | - Krunalkumar Patel
- Department of Internal MedicineSt. Mary Medical CenterLanghornePAUSA
| | | | - Sona Franklin
- Department of Internal MedicineSt. Mary Medical CenterLanghornePAUSA
| | - Harsh Patel
- Department of Internal MedicineLouis A Weiss Memorial HospitalChicagoILUSA
| | - Shruti Jesani
- Department of Internal MedicineTrinitas Regional Medical CenterElizabethNJUSA
| | | | - Vraj Shah
- Division of CardiologyMedical College of BarodaVadodaraIndia
| | | | | | - Steven Kutalek
- Department of CardiologyDrexel University College of MedicinePhiladelphiaPAUSA
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Hooper JS, Taylor-Clark TE. Irritant Inhalation Evokes P Wave Morphological Changes in Spontaneously Hypertensive Rats via Reflex Modulation of the Autonomic Nervous System. Front Physiol 2021; 12:642299. [PMID: 34385930 PMCID: PMC8353281 DOI: 10.3389/fphys.2021.642299] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 07/06/2021] [Indexed: 01/09/2023] Open
Abstract
Irritant inhalation is associated with increased incidence of atrial fibrillation (AF) and stroke. Irritant inhalation acutely regulates cardiac function via autonomic reflexes. Increases in parasympathetic and sympathetic reflexes may increase atrial susceptibility to ectopic activity and the initiation of arrhythmia such as AF. Both age and hypertension are risk factors for AF. We have shown that irritant-evoked pulmonary–cardiac reflexes are remodeled in spontaneously hypertensive (SH) rats to include a sympathetic component in addition to the parasympathetic reflex observed in normotensive Wistar-Kyoto (WKY) rats. Here, we analyzed P wave morphology in 15-week old WKY and SH rats during inhalation of the transient receptor potential ankyrin 1 agonist allyl isothiocyanate (AITC). P Wave morphology was normal during vehicle inhalation but was variably modulated by AITC. AITC increased RR intervals (RRi), PR intervals, and the P Wave duration. In SH rats only, AITC inhalation increased the occurrence of negative P waves. The incidence of AITC-evoked negative P waves in SH rats was dependent on RRi, increasing during bradycardic and tachycardic cardiac cycles. Inhibition of both parasympathetic (using atropine) and sympathetic (using atenolol) components of the pulmonary–cardiac reflex decreased the incidence of negative P waves. Lastly, the probability of evoking a negative P Wave was increased by the occurrence of preceding negative P waves. We conclude that the remodeled irritant-evoked pulmonary–cardiac reflex in SH rats provides a substrate for altered P Wave morphologies. These are likely ectopic atrial beats that could provide a trigger for AF initiation in structurally remodeled atria.
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Affiliation(s)
- J Shane Hooper
- Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Thomas E Taylor-Clark
- Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
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Ramlugun GS, Sands GB, Zhao J, LeGrice IJ, Smaill BH. A novel system for mapping regional electrical properties and characterizing arrhythmia in isolated intact rat atria. Am J Physiol Heart Circ Physiol 2021; 321:H412-H421. [PMID: 34213393 DOI: 10.1152/ajpheart.00185.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Detailed global maps of atrial electrical activity are needed to understand mechanisms of atrial rhythm disturbance in small animal models of heart disease. To date, optical mapping systems have not provided enough spatial resolution across sufficiently extensive regions of intact atrial preparations to achieve this goal. The aim of this study was to develop an integrated platform for quantifying regional electrical properties and analyzing reentrant arrhythmia in a biatrial preparation. Intact atria from 6/7-mo-old female spontaneously hypertensive rats (SHRs; n = 6) were isolated and secured in a constant flow superfusion chamber at 37°C. Optical mapping was performed with the membrane-voltage dye di-4-ANEPPS using LED excitation and a scientific complementary metal-oxide semiconductor (sCMOS) camera. Programmed stimulus trains were applied from right atrial (RA) and left atrial (LA) sites to assess rate-dependent electrical behavior and to induce atrial arrhythmia. Signal-to-noise ratio was improved by sequential processing steps that included spatial smoothing, temporal filtering, and, in stable rhythms, ensemble-averaging. Activation time, repolarization time, and action potential duration (APD) maps were constructed at high spatial resolution for a wide range of coupling intervals. These data were highly consistent within and between experiments. They confirmed preferential atrial conduction pathways and demonstrated distinct medial-to-lateral APD gradients. We also showed that reentrant arrhythmias induced in this preparation were explained by the spatial variation of these electrical properties. Our new methodology provides a robust means of 1) quantifying regional electrical properties in the intact rat atria at higher spatiotemporal resolution than previously reported, and 2) characterizing reentrant arrhythmia and analyzing mechanisms that give rise to it.NEW & NOTEWORTHY Despite wide-ranging optical mapping studies, detailed information on regional atrial electrical properties in small animal models of heart disease and how these contribute to reentrant arrhythmia remains limited. We have developed a novel experimental platform that enables both to be achieved in a geometrically intact isolated rat bi-atrial preparation.
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Affiliation(s)
- Girish S Ramlugun
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Gregory B Sands
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Jichao Zhao
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Ian J LeGrice
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.,Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Bruce H Smaill
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.,Department of Physiology, University of Auckland, Auckland, New Zealand
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9
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Liao LZ, Wen XY, Zhang SZ, Li WD, Zhuang XD. Hypertension and Atrial Fibrillation: A Study on Epidemiology and Mendelian Randomization Causality. Front Cardiovasc Med 2021; 8:644405. [PMID: 33834045 PMCID: PMC8021766 DOI: 10.3389/fcvm.2021.644405] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/08/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction: Hypertension (HT) and atrial fibrillation (AF) often coexist. However, the causality between these two conditions remains to be determined. Methods: We used individual participant data from the Atherosclerosis Risk in Communities (ARIC) prospective cohort with 9,474 participants. HT was ascertained at visit 1 (1987–1989), and incident AF was identified by ECGs conducted during study examinations at each visit, hospital discharge codes, and death certificates. We used the Kaplan–Meier estimate to compute the cumulative incidence of AF by the HT subgroup. Then we used Cox hazard regression model to assess the association between HT and incident AF. The causality between genetically determined HT and AF was analyzed by the two-sample Mendelian randomization (MR) based on publicly summarized genome-wide association studies (GWASs) data. Results: A total of 1,414 cases (14.9%) of AF were identified during the follow-up period (median 24.1 years). After adjusting for all covariates, the hazard ratio between the participants with HT and incident AF was 1.50 [95% confidence interval (CI) 1.29–1.73]. In the HT → AF MR analysis, we detected a causal correlation between HT and AF (OR: 1.90, 95% CI 1.18–3.04, P = 0.01) with no evidence of heterogeneity from single-nucleotide polymorphisms. Besides, the genetically determined SBP and DBP (10 mmHg) were consistently associated with a higher risk of AF. Conclusions: In the ARIC study, the incident AF increased by 50% in patients with HT. In the MR analysis, our results supported causal inference between HT and AF.
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Affiliation(s)
- Li-Zhen Liao
- Guangzhou Higher Education Mega Center, Guangdong Pharmaceutical University, Guangzhou, China.,Guangdong Engineering Research Center for Light and Health, Guangzhou Higher Education Mega Center, Guangzhou, China.,Guangdong Key Laboratory of Pharmaceutical Bioactive Substances, Guangdong Pharmaceutical University, Guangzhou, China
| | - Xiu-Yun Wen
- Guangzhou Higher Education Mega Center, Guangdong Pharmaceutical University, Guangzhou, China.,Guangdong Engineering Research Center for Light and Health, Guangzhou Higher Education Mega Center, Guangzhou, China.,Guangdong Key Laboratory of Pharmaceutical Bioactive Substances, Guangdong Pharmaceutical University, Guangzhou, China
| | - Shao-Zhao Zhang
- The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Wei-Dong Li
- Guangzhou Higher Education Mega Center, Guangdong Pharmaceutical University, Guangzhou, China.,Guangdong Engineering Research Center for Light and Health, Guangzhou Higher Education Mega Center, Guangzhou, China.,Guangdong Key Laboratory of Pharmaceutical Bioactive Substances, Guangdong Pharmaceutical University, Guangzhou, China
| | - Xiao-Dong Zhuang
- The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
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Zhang Y, Qi Y, Li JJ, He WJ, Gao XH, Zhang Y, Sun X, Tong J, Zhang J, Deng XL, Du XJ, Xie W. Stretch-induced sarcoplasmic reticulum calcium leak is causatively associated with atrial fibrillation in pressure-overloaded hearts. Cardiovasc Res 2021; 117:1091-1102. [PMID: 32531044 DOI: 10.1093/cvr/cvaa163] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 01/06/2020] [Accepted: 06/05/2020] [Indexed: 12/21/2022] Open
Abstract
AIMS Despite numerous reports documenting an important role of hypertension in the development of atrial fibrillation (AF), the detailed mechanism underlying the pathological process remains incompletely understood. Here, we aim to test the hypothesis that diastolic sarcoplasmic reticulum (SR) Ca2+ leak in atrial myocytes, induced by mechanical stretch due to elevated pressure in the left atrium (LA), plays an essential role in the AF development in pressure-overloaded hearts. METHODS AND RESULTS Isolated mouse atrial myocytes subjected to acute axial stretch displayed an immediate elevation of SR Ca2+ leak. Using a mouse model of transverse aortic constriction (TAC), the relation between stretch, SR Ca2+ leak, and AF susceptibility was further tested. At 36 h post-TAC, SR Ca2+ leak in cardiomyocytes from the LA (with haemodynamic stress), but not right atrium (without haemodynamic stress), significantly increased, which was further elevated at 4 weeks post-TAC. Accordingly, AF susceptibility to atrial burst pacing in the 4-week TAC mice were also significantly increased, which was unaffected by inhibition of atrial fibrosis or inflammation via deletion of galectin-3. Western blotting revealed that type 2 ryanodine receptor (RyR2) in left atrial myocytes of TAC mice was oxidized due to activation and up-regulation of Nox2 and Nox4. Direct rescue of dysfunctional RyR2 with dantrolene or rycal S107 reduced diastolic SR Ca2+ leak in left atrial myocytes and prevented atrial burst pacing stimulated AF. CONCLUSION Our study demonstrated for the first time the increased SR Ca2+ leak mediated by enhanced oxidative stress in left atrial myocytes that is causatively associated with higher AF susceptibility in pressure-overloaded hearts.
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Affiliation(s)
- Yi Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Ying Qi
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 West Xianning Road, Xi'an, Shaanxi 710049, China
| | - Jing-Jing Li
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 West Xianning Road, Xi'an, Shaanxi 710049, China
| | - Wen-Jin He
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 West Xianning Road, Xi'an, Shaanxi 710049, China
| | - Xiao-Hang Gao
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 West Xianning Road, Xi'an, Shaanxi 710049, China
| | - Yu Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Xia Sun
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Jie Tong
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 West Xianning Road, Xi'an, Shaanxi 710049, China
| | - Jianbao Zhang
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 West Xianning Road, Xi'an, Shaanxi 710049, China
| | - Xiu-Ling Deng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
- Cardiovascular Research Centre, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Xiao-Jun Du
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Wenjun Xie
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 West Xianning Road, Xi'an, Shaanxi 710049, China
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11
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Aguilar M, Rose RA, Takawale A, Nattel S, Reilly S. New aspects of endocrine control of atrial fibrillation and possibilities for clinical translation. Cardiovasc Res 2021; 117:1645-1661. [PMID: 33723575 PMCID: PMC8208746 DOI: 10.1093/cvr/cvab080] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/25/2021] [Accepted: 03/11/2021] [Indexed: 12/20/2022] Open
Abstract
Hormones are potent endo-, para-, and autocrine endogenous regulators of the function of multiple organs, including the heart. Endocrine dysfunction promotes a number of cardiovascular diseases, including atrial fibrillation (AF). While the heart is a target for endocrine regulation, it is also an active endocrine organ itself, secreting a number of important bioactive hormones that convey significant endocrine effects, but also through para-/autocrine actions, actively participate in cardiac self-regulation. The hormones regulating heart-function work in concert to support myocardial performance. AF is a serious clinical problem associated with increased morbidity and mortality, mainly due to stroke and heart failure. Current therapies for AF remain inadequate. AF is characterized by altered atrial function and structure, including electrical and profibrotic remodelling in the atria and ventricles, which facilitates AF progression and hampers its treatment. Although features of this remodelling are well-established and its mechanisms are partly understood, important pathways pertinent to AF arrhythmogenesis are still unidentified. The discovery of these missing pathways has the potential to lead to therapeutic breakthroughs. Endocrine dysfunction is well-recognized to lead to AF. In this review, we discuss endocrine and cardiocrine signalling systems that directly, or as a consequence of an underlying cardiac pathology, contribute to AF pathogenesis. More specifically, we consider the roles of products from the hypothalamic-pituitary axis, the adrenal glands, adipose tissue, the renin–angiotensin system, atrial cardiomyocytes, and the thyroid gland in controlling atrial electrical and structural properties. The influence of endocrine/paracrine dysfunction on AF risk and mechanisms is evaluated and discussed. We focus on the most recent findings and reflect on the potential of translating them into clinical application.
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Affiliation(s)
- Martin Aguilar
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montréal, QC, Canada.,Department of Pharmacology and Physiology/Institute of Biomedical Engineering, Université de Montréal, Montréal, QC, Canada
| | - Robert A Rose
- Department of Cardiac Sciences, Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, Health Research Innovation Center, University of Calgary, AB, Canada
| | - Abhijit Takawale
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montréal, QC, Canada.,Department of Pharmacology and Physiology/Institute of Biomedical Engineering, Université de Montréal, Montréal, QC, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - Stanley Nattel
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada.,Faculty of Medicine, Department of Pharmacology and Physiology, and Research Centre, Montreal Heart Institute and University of Montreal, Montreal, QC, Canada.,Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Germany.,IHU LIRYC and Fondation Bordeaux Université, Bordeaux, France
| | - Svetlana Reilly
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, British Heart Foundation Centre of Research Excellence, University of Oxford, John Radcliffe Hospital, Oxford, UK
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12
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Zheng Y, Xie Z, Li J, Chen C, Cai W, Dong Y, Xue R, Liu C. Meta-analysis of metabolic syndrome and its individual components with risk of atrial fibrillation in different populations. BMC Cardiovasc Disord 2021; 21:90. [PMID: 33588759 PMCID: PMC7885417 DOI: 10.1186/s12872-021-01858-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 01/06/2021] [Indexed: 11/10/2022] Open
Abstract
Background Recent studies have reported the effects of metabolic syndrome (MetS) and its components on atrial fibrillation (AF), but the results remain controversial. Therefore, we performed a meta-analysis to evaluate the relationship between MetS and AF risk.
Methods Studies were searched from the Cochrane library, PubMed, and Embase databases through May 2020. Adjusted hazard ratios (HRs) and its corresponding 95% confidence intervals (CIs) were extracted and then pooled by using a random effects model. Results A total of 6 observational cohort studies were finally included. In the pooled analysis, MetS was associated with an increased risk of AF (HR 1.57; 95% CI 1.40–1.77; P < 0.01). And the components of MetS including abdominal obesity (HR 1.37; 95% CI 1.36–1.38; P < 0.01), elevated blood pressure (HR 1.56; 95% CI 1.46–1.66; P < 0.01), elevated fasting glucose (HR 1.18; 95% CI 1.15–1.21; P < 0.01) and low high density cholesterol (HDL) (HR 1.18; 95% CI 1.06–1.32; P < 0.01) was also associated with an increased risk of AF, while high triglyceride (HR 0.99; 95% CI 0.87–1.11, P = 0.82) was not. Conclusions Our present meta-analysis suggested that MetS, as well as its components including abdominal obesity, elevated blood pressure, elevated fasting glucose and low HDL cholesterol were associated with an increase in the risk of AF.
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Affiliation(s)
- Ying Zheng
- Department of Otorhinolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China.,Department of Cardiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510080, China
| | - Zengshuo Xie
- Department of Cardiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510080, China.,NHC Key Laboratory of Assisted Circulation (Sun Yat-Sen University), Guangzhou, 510080, China
| | - Jiayong Li
- Department of Cardiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510080, China.,NHC Key Laboratory of Assisted Circulation (Sun Yat-Sen University), Guangzhou, 510080, China
| | - Chen Chen
- Department of Cardiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510080, China.,NHC Key Laboratory of Assisted Circulation (Sun Yat-Sen University), Guangzhou, 510080, China
| | - Wenting Cai
- Department of Cardiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510080, China.,NHC Key Laboratory of Assisted Circulation (Sun Yat-Sen University), Guangzhou, 510080, China
| | - Yugang Dong
- Department of Cardiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510080, China.,NHC Key Laboratory of Assisted Circulation (Sun Yat-Sen University), Guangzhou, 510080, China.,National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China
| | - Ruicong Xue
- Department of Cardiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510080, China.,NHC Key Laboratory of Assisted Circulation (Sun Yat-Sen University), Guangzhou, 510080, China.,National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China
| | - Chen Liu
- Department of Cardiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510080, China. .,NHC Key Laboratory of Assisted Circulation (Sun Yat-Sen University), Guangzhou, 510080, China. .,National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China.
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13
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Murninkas M, Gillis R, Lee DI, Elyagon S, Bhandarkar NS, Levi O, Polak R, Klapper-Goldstein H, Mulla W, Etzion Y. A new implantable tool for repeated assessment of supraventricular electrophysiology and atrial fibrillation susceptibility in freely moving rats. Am J Physiol Heart Circ Physiol 2021; 320:H713-H724. [PMID: 33337966 DOI: 10.1152/ajpheart.00676.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 12/17/2020] [Accepted: 12/17/2020] [Indexed: 12/21/2022]
Abstract
The complex pathophysiology of atrial fibrillation (AF) is governed by multiple risk factors in ways that are still elusive. Basic electrophysiological properties, including atrial effective refractory period (AERP) and conduction velocity, are major factors determining the susceptibility of the atrial myocardium to AF. Although there is a great need for affordable animal models in this field of research, in vivo rodent studies are limited by technical challenges. Recently, we introduced an implantable system for long-term assessment of AF susceptibility in ambulatory rats. However, technical considerations did not allow us to perform concomitant supraventricular electrophysiology measurements. Here, we designed a novel quadripolar electrode specifically adapted for comprehensive atrial studies in ambulatory rats. Electrodes were fabricated from medical-grade silicone, four platinum-iridium poles, and stainless-steel fixating pins. Initial quality validation was performed ex vivo, followed by implantation in adult rats and repeated electrophysiological studies 1, 4, and 8 wk postimplantation. Capture threshold was stable. Baseline AERP values (38.1 ± 2.3 and 39.5 ± 2.0 using 70-ms and 120-ms S1-S1 cycle lengths, respectively) confirmed the expected absence of rate adaptation in the unanesthetized state and validated our prediction that markedly higher values reported under anesthesia are nonphysiological. Evaluation of AF substrate in parallel with electrophysiological parameters validated our recent finding of a gradual increase in AF susceptibility over time and demonstrated that this phenomenon is associated with an electrical remodeling process characterized by AERP shortening. Our findings indicate that the miniature quadripolar electrode is a potent new tool, which opens a window of opportunities for better utilization of rats in AF research.NEW & NOTEWORTHY Rodents are increasingly used in AF research. However, technical challenges restrict long-term supraventricular electrophysiology studies in these species. Here, we developed an implantable electrode adapted for such studies in the rat. Our findings indicate that this new tool is effective for long-term follow-up of critical parameters such as atrial refractoriness. Obtained data shed light on the normal electrophysiology and on the increased AF susceptibility that develops in rats with implanted atrial electrodes over time.
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Affiliation(s)
- Michael Murninkas
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Regenerative Medicine and Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Roni Gillis
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Regenerative Medicine and Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Danielle I Lee
- College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
- Canadian Centre for Agri-Food Research in Health and Medicine (CCARM), St. Boniface Hospital Research Centre, Winnipeg, Manitoba, Canada
| | - Sigal Elyagon
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Regenerative Medicine and Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Nikhil S Bhandarkar
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Or Levi
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Regenerative Medicine and Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Rotem Polak
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Regenerative Medicine and Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Hadar Klapper-Goldstein
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Regenerative Medicine and Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Wesam Mulla
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Regenerative Medicine and Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Yoram Etzion
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Regenerative Medicine and Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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14
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Hyman MC, Levin MG, Gill D, Walker VM, Georgakis MK, Davies NM, Marchlinski FE, Damrauer SM. Genetically Predicted Blood Pressure and Risk of Atrial Fibrillation. Hypertension 2021; 77:376-382. [PMID: 33390040 PMCID: PMC7803440 DOI: 10.1161/hypertensionaha.120.16191] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Observational studies have shown an association between hypertension and atrial fibrillation (AF). Aggressive blood pressure management in patients with known AF reduces overall arrhythmia burden, but it remains unclear whether hypertension is causative for AF. To address this question, this study explored the relationship between genetic predictors of blood pressure and risk of AF. We secondarily explored the relationship between genetically proxied use of antihypertensive drugs and risk of AF. Two-sample Mendelian randomization was performed using an inverse-variance weighted meta-analysis with weighted median Mendelian randomization and Egger intercept tests performed as sensitivity analyses. Summary statistics for systolic blood pressure, diastolic blood pressure, and pulse pressure were obtained from the International Consortium of Blood Pressure and the UK Biobank discovery analysis and AF from the 2018 Atrial Fibrillation Genetics Consortium multiethnic genome-wide association studies. Increases in genetically proxied systolic blood pressure, diastolic blood pressure, or pulse pressure by 10 mm Hg were associated with increased odds of AF (systolic blood pressure: odds ratio [OR], 1.17 [95% CI, 1.11-1.22]; P=1×10-11; diastolic blood pressure: OR, 1.25 [95% CI, 1.16-1.35]; P=3×10-8; pulse pressure: OR, 1.1 [95% CI, 1.0-1.2]; P=0.05). Decreases in systolic blood pressure by 10 mm Hg estimated by genetic proxies of antihypertensive medications showed calcium channel blockers (OR, 0.66 [95% CI, 0.57-0.76]; P=8×10-9) and β-blockers (OR, 0.61 [95% CI, 0.46-0.81]; P=6×10-4) decreased the risk of AF. Blood pressure-increasing genetic variants were associated with increased risk of AF, consistent with a causal relationship between blood pressure and AF. These data support the concept that blood pressure reduction with calcium channel blockade or β-blockade could reduce the risk of AF.
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Affiliation(s)
- Matthew C Hyman
- From the Division of Cardiovascular Medicine (M.C.H., M.G.L., F.E.M.), University of Pennsylvania Perelman School of Medicine, Philadelphia
| | - Michael G Levin
- From the Division of Cardiovascular Medicine (M.C.H., M.G.L., F.E.M.), University of Pennsylvania Perelman School of Medicine, Philadelphia.,Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA (M.G.L., S.M.D.)
| | - Dipender Gill
- Department of Epidemiology and Biostatistics, School of Public Health (D.G.), Imperial College London, United Kingdom.,Department of Medicine, Centre for Pharmacology and Therapeutics, Hammersmith Campus (D.G.), Imperial College London, United Kingdom.,Department of Genetics, Novo Nordisk Research Centre Oxford, Old Road Campus, United Kingdom (D.G.).,Clinical Pharmacology and Therapeutics Section, Institute of Medical and Biomedical Education and Institute for Infection and Immunity, St George's, University of London, United Kingdom (D.G.).,Clinical Pharmacology Group, Pharmacy and Medicines Directorate, St George's University Hospitals NHS Foundation Trust, London, United Kingdom (D.G.)
| | - Venexia M Walker
- Department of Surgery (V.M.W., S.M.D.), University of Pennsylvania Perelman School of Medicine, Philadelphia.,Medical Research Council Integrative Epidemiology Unit (V.M.W., N.D.), University of Bristol, United Kingdom.,Bristol Medical School: Population Health Sciences (V.M.W.), University of Bristol, United Kingdom
| | - Marios K Georgakis
- Institute for Stroke and Dementia Research, University Hospital, Ludwig-Maximilians-University LMU, Munich, Germany (M.K.G.)
| | - Neil M Davies
- Medical Research Council Integrative Epidemiology Unit (V.M.W., N.D.), University of Bristol, United Kingdom
| | - Francis E Marchlinski
- From the Division of Cardiovascular Medicine (M.C.H., M.G.L., F.E.M.), University of Pennsylvania Perelman School of Medicine, Philadelphia
| | - Scott M Damrauer
- Department of Surgery (V.M.W., S.M.D.), University of Pennsylvania Perelman School of Medicine, Philadelphia.,Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA (M.G.L., S.M.D.)
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15
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Lee HC, Shin SJ, Huang JK, Lin MY, Lin YH, Ke LY, Jiang HJ, Tsai WC, Chao MF, Lin YH. The role of postprandial very-low-density lipoprotein in the development of atrial remodeling in metabolic syndrome. Lipids Health Dis 2020; 19:210. [PMID: 32962696 PMCID: PMC7507670 DOI: 10.1186/s12944-020-01386-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 09/10/2020] [Indexed: 11/30/2022] Open
Abstract
Background Negatively charged very-low-density lipoprotein (VLDL-χ) in metabolic syndrome (MetS) patients exerts cytotoxic effects on endothelial cells and atrial myocytes. Atrial cardiomyopathy, manifested by atrial remodeling with a dilated diameter, contributes to atrial fibrillation pathogenesis and predicts atrial fibrillation development. The correlation of VLDL-χ with atrial remodeling is unknown. This study investigated the association between VLDL-χ and remodeling of left atrium. Methods Consecutively, 87 MetS and 80 non-MetS individuals between 23 and 74 years old (50.6% men) without overt cardiovascular diseases were included in the prospective cohort study. Blood samples were collected while fasting and postprandially (at 0.5, 1, 2, and 4 h after a unified meal). VLDL was isolated by ultracentrifugation; the percentile concentration of VLDL-χ (%) was determined by ultra-performance liquid chromatography. The correlations of left atrium diameter (LAD) with variables including VLDL-χ, LDL-C, HDL-C, triglycerides, glucose, and blood pressure, were analyzed by multiple linear regression models. A hierarchical linear model was conducted to test the independencies of each variable’s correlation with LAD. Results The mean LAD was 3.4 ± 0.5 cm in non-MetS subjects and 3.9 ± 0.5 cm in MetS patients (P < 0.01). None of the fasting lipid profiles were associated with LAD. VLDL-χ, BMI, waist circumference, hip circumference, and blood pressure were positively correlated with LAD (all P < 0.05) after adjustment for age and sex. Significant interactions between VLDL-χ and blood pressure, waist circumference, and hip circumference were observed. When adjusted for obesity- and blood pressure-related variables, 2-h postprandial VLDL-χ (mean 1.30 ± 0.61%) showed a positive correlation with LAD in MetS patients. Each 1% VLDL-χ increase was estimated to increase LAD by 0.23 cm. Conclusions Postprandial VLDL-χ is associated with atrial remodeling particularly in the MetS group. VLDL-χ is a novel biomarker and may be a therapeutic target for atrial cardiomyopathy in MetS patients. Trial registration ISRCTN 69295295. Retrospectively registered 9 June 2020.
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Affiliation(s)
- Hsiang-Chun Lee
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan. .,Lipid Science and Aging Research Center, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. .,Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan. .,Department of Internal Medicine, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. .,Institute/Center of Medical Science and Technology, National Sun Yat-sen University, Kaohsiung, Taiwan.
| | - Shyi-Jang Shin
- Department of Internal Medicine, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jih-Kai Huang
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ming-Yen Lin
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yu-Hsun Lin
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Liang-Yin Ke
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Lipid Science and Aging Research Center, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - He-Jiun Jiang
- Department of Metabolism, Affiliated Hospital of Kaohsiung Medical University, Kaohsiung, Taiwan.,College of Medicine, I-Shou University, Kaohsiung, Taiwan
| | - Wei-Chung Tsai
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.,Department of Internal Medicine, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Min-Fang Chao
- Department of Medical Imaging, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yi-Hsiung Lin
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
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16
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Jansen HJ, Bohne LJ, Gillis AM, Rose RA. Atrial remodeling and atrial fibrillation in acquired forms of cardiovascular disease. Heart Rhythm O2 2020; 1:147-159. [PMID: 34113869 PMCID: PMC8183954 DOI: 10.1016/j.hroo.2020.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Atrial fibrillation (AF) is prevalent in common conditions and acquired forms of heart disease, including diabetes mellitus (DM), hypertension, cardiac hypertrophy, and heart failure. AF is also prevalent in aging. Although acquired heart disease is common in aging individuals, age is also an independent risk factor for AF. Importantly, not all individuals age at the same rate. Rather, individuals of the same chronological age can vary in health status from fit to frail. Frailty can be quantified using a frailty index, which can be used to assess heterogeneity in individuals of the same chronological age. AF is thought to occur in association with electrical remodeling due to changes in ion channel expression or function as well as structural remodeling due to fibrosis, myocyte hypertrophy, or adiposity. These forms of remodeling can lead to triggered activity and electrical re-entry, which are fundamental mechanisms of AF initiation and maintenance. Nevertheless, the underlying determinants of electrical and structural remodeling are distinct in different conditions and disease states. In this focused review, we consider the factors leading to atrial electrical and structural remodeling in human patients and animal models of acquired cardiovascular disease or associated risk factors. Our goal is to identify similarities and differences in the cellular and molecular bases for atrial electrical and structural remodeling in conditions including DM, hypertension, hypertrophy, heart failure, aging, and frailty.
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Affiliation(s)
- Hailey J Jansen
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Loryn J Bohne
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Anne M Gillis
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Robert A Rose
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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17
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Lee JS, Greco L, Migirov A, Li Y, Gerdes AM, Zhang Y. Chronic Dantrolene Treatment Does Not Affect Hypertension, but Attenuates Sympathetic Stimulation Enhanced Atrial Fibrillation Inducibility in SHR. Am J Hypertens 2020; 33:407-413. [PMID: 32060500 DOI: 10.1093/ajh/hpaa021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/11/2019] [Accepted: 02/11/2020] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Ryanodine receptor (RyR) dysfunction in skeletal muscle (RyR1) leads to malignant hyperthermia, and in cardiac muscle (RyR2) triggers cardiac arrhythmias. We hypothesized that RyR dysfunction in vascular smooth muscle could increase vascular resistance and hypertension, and may contribute to increased atrial fibrillation (AF) in hypertension. Thus, stabilizing RyR function with chronic dantrolene treatment may attenuate hypertension and AF inducibility in spontaneously hypertensive rats (SHR). METHODS Male SHR (16 weeks old) were randomized into vehicle- (n = 10) and dantrolene-treated (10 mg/kg/day, n = 10) groups for 4 weeks. Wistar Kyoto (WKY, n = 11) rats served as controls. Blood pressures (BP) were monitored before and during the 4-week treatment. After 4-week treatment, direct BP, echocardiography, and hemodynamics were recorded. AF inducibility tests were performed in vivo at baseline and repeated under sympathetic stimulation (SS). RESULTS Compared with WKY, SHR had significantly higher BP throughout the experimental period. Dantrolene treatment had no effect on BP levels in SHR (final systolic BP 212 ± 9 mm Hg in vehicle group vs. 208 ± 16 mm Hg in dantrolene group, P > 0.05). AF inducibility was very low and not significantly different between 5-month-old WKY and SHR at baseline. However, under SS, AF inducibility and duration were significantly increased in SHR (20% in WKY vs. 60% in SHR-vehicle, P<0.05). Dantrolene treatment significantly attenuated AF inducibility under SS in SHR (60% in vehicle vs. 20% in dantrolene, P < 0.05). CONCLUSIONS Stabilizing RyR with chronic dantrolene treatment does not affect hypertension development in SHR. SHR has increased vulnerability to AF induction under SS, which can be attenuated with dantrolene treatment.
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Affiliation(s)
- Jae S Lee
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York, USA
| | - Lisa Greco
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York, USA
| | - Allan Migirov
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York, USA
| | - Ying Li
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York, USA
| | - A Martin Gerdes
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York, USA
| | - Youhua Zhang
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York, USA
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18
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Scardigli M, Cannazzaro S, Coppini R, Crocini C, Yan P, Loew LM, Sartiani L, Cerbai E, Pavone FS, Sacconi L, Ferrantini C. Arrhythmia susceptibility in a rat model of acute atrial dilation. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 154:21-29. [PMID: 32063273 DOI: 10.1016/j.pbiomolbio.2019.08.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 08/17/2019] [Accepted: 08/27/2019] [Indexed: 12/11/2022]
Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia, associated with an increased risk of stroke and heart failure. Acute AF occurs in response to sudden increases of atrial hemodynamic load, leading to atrial stretch. The mechanisms of stretch-induced AF were investigated in large mammals with controversial results. We optimized an approach to monitor rat atrial electrical activity using a red-shifted voltage sensitive dye (VSD). The methodology includes cauterization of the main ventricular coronary arteries, allowing improved atrial staining by the VSD and appropriate atrial perfusion for long experiments. Next, we developed a rat model of acute biatrial dilation (ABD) through the insertion of latex balloons into both atria, which could be inflated with controlled volumes. A chronic model of atrial dilation (spontaneous hypertensive rats; SHR) was used for comparison. ABD was performed on atria from healthy Wistar-Kyoto (WKY) rats (WKY-ABD). The atria were characterized in terms of arrhythmias susceptibility, action potential duration and conduction velocity. The occurrence of arrhythmias in WKY-ABD was significantly higher compared to non-dilated WKY atria. In WKY-ABD we found a reduction of conduction velocity, similar to that observed in SHR atria, while action potential duration was unchanged. Low-dose caffeine was used to introduce a drop of CV in WKY atria (WKY-caff), quantitatively similar to the one observed after ABD, but no increased arrhythmia susceptibility was observed with caffeine only. In conclusion, CV decrease is not sufficient to promote arrhythmias; enlargement of atrial surface is essential to create a substrate for acute reentry-based arrhythmias.
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Affiliation(s)
- M Scardigli
- European Laboratory for Non-Linear Spectroscopy, 50019, Sesto Fiorentino (FI), Italy
| | - S Cannazzaro
- National Institute of Optics, National Research Council, 50125, Florence, Italy
| | - R Coppini
- Division of Pharmacology, Department "NeuroFarBa,", University of Florence, 50139, Florence, Italy
| | - C Crocini
- Department of Molecular, Cellular, and Developmental Biology and BioFrontiers Institute, University of Colorado, Boulder, USA
| | - P Yan
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, CT, 06030, USA
| | - L M Loew
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, CT, 06030, USA
| | - L Sartiani
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, CT, 06030, USA
| | - E Cerbai
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, CT, 06030, USA
| | - F S Pavone
- European Laboratory for Non-Linear Spectroscopy, 50019, Sesto Fiorentino (FI), Italy; National Institute of Optics, National Research Council, 50125, Florence, Italy; Department of Physics and Astronomy, University of Florence, 50019, Sesto Fiorentino (FI), Italy
| | - L Sacconi
- European Laboratory for Non-Linear Spectroscopy, 50019, Sesto Fiorentino (FI), Italy; National Institute of Optics, National Research Council, 50125, Florence, Italy
| | - C Ferrantini
- European Laboratory for Non-Linear Spectroscopy, 50019, Sesto Fiorentino (FI), Italy; Division of Physiology, Department of Experimental and Clinical Medicine, University of Florence, 50134, Florence, Italy.
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The Pathogenic Role of Very Low Density Lipoprotein on Atrial Remodeling in the Metabolic Syndrome. Int J Mol Sci 2020; 21:ijms21030891. [PMID: 32019138 PMCID: PMC7037013 DOI: 10.3390/ijms21030891] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/24/2020] [Accepted: 01/28/2020] [Indexed: 12/16/2022] Open
Abstract
Atrial fibrillation (AF) is the most common persistent arrhythmia, and can lead to systemic thromboembolism and heart failure. Aging and metabolic syndrome (MetS) are major risks for AF. One of the most important manifestations of MetS is dyslipidemia, but its correlation with AF is ambiguous in clinical observational studies. Although there is a paradoxical relationship between fasting cholesterol and AF incidence, the benefit from lipid lowering therapy in reduction of AF is significant. Here, we reviewed the health burden from AF and MetS, the association between two disease entities, and the metabolism of triglyceride, which is elevated in MetS. We also reviewed scientific evidence for the mechanistic links between very low density lipoproteins (VLDL), which primarily carry circulatory triglyceride, to atrial cardiomyopathy and development of AF. The effects of VLDL to atria suggesting pathogenic to atrial cardiomyopathy and AF include excess lipid accumulation, direct cytotoxicity, abbreviated action potentials, disturbed calcium regulation, delayed conduction velocities, modulated gap junctions, and sarcomere protein derangements. The electrical remodeling and structural changes in concert promote development of atrial cardiomyopathy in MetS and ultimately lead to vulnerability to AF. As VLDL plays a major role in lipid metabolism after meals (rather than fasting state), further human studies that focus on the effects/correlation of postprandial lipids to atrial remodeling are required to determine whether VLDL-targeted therapy can reduce MetS-related AF. On the basis of our scientific evidence, we propose a pivotal role of VLDL in MetS-related atrial cardiomyopathy and vulnerability to AF.
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High hydrostatic pressure induces atrial electrical remodeling through angiotensin upregulation mediating FAK/Src pathway activation. J Mol Cell Cardiol 2020; 140:10-21. [PMID: 32006532 DOI: 10.1016/j.yjmcc.2020.01.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 01/15/2020] [Accepted: 01/27/2020] [Indexed: 01/02/2023]
Abstract
Hypertension is an independent risk factor for atrial fibrillation (AF), although its specific mechanisms remain unclear. Previous research has been focused on cyclic stretch, ignoring the role of high hydrostatic pressure. The present study aimed to explore the effect of high hydrostatic pressure stimulation on electrical remodeling in atrial myocytes and its potential signaling pathways. Experiments were performed on left atrial appendages from patients with chronic AF or sinus rhythm, spontaneously hypertensive rats (SHRs) treated with or without valsartan (10 mg/kg/day) and HL-1 cells were exposed to high hydrostatic pressure using a self-developed device. Whole-cell patch-clamp recordings and western blots demonstrated that the amplitudes of ICa,L, Ito, and IKur were reduced in AF patients with corresponding changes in protein expression. Angiotensin protein levels increased and Ang1-7 decreased, while focal adhesion kinase (FAK) and Src kinase were enhanced in atrial tissue from AF patients and SHRs. After rapid atrial pacing, AF inducibility in SHR was significantly higher, accompanied by a decrease in ICa,L, upregulation of Ito and IKur, and a shortened action potential duration. Angiotensin upregulation and FAK/Src activation in SHR were inhibited by angiotensin type 1 receptor inhibitor valsartan, thus, preventing electrical remodeling and reducing AF susceptibility. These results were verified in HL-1 cells treated with high hydrostatic pressure, and demonstrated that electrical remodeling regulated by the FAK-Src pathway could be modulated by valsartan. The present study indicated that high hydrostatic pressure stimulation increases AF susceptibility by activating the renin-angiotensin system and FAK-Src pathway in atrial myocytes.
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An implantable system for long-term assessment of atrial fibrillation substrate in unanesthetized rats exposed to underlying pathological conditions. Sci Rep 2020; 10:553. [PMID: 31953473 PMCID: PMC6969190 DOI: 10.1038/s41598-020-57528-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 12/16/2019] [Indexed: 02/02/2023] Open
Abstract
Atrial fibrillation (AF) is a progressive arrhythmia with underlying mechanisms that are not fully elucidated, partially due to lack of reliable and affordable animal models. Here, we introduce a system for long-term assessment of AF susceptibility (substrate) in ambulatory rats implanted with miniature electrodes on the atrium. Rats were subjected to excessive aldosterone (Aldo) or solvent only (Sham). An additional group was exposed to myocardial infarction (MI). AF substrate was tested two- and four-weeks post implantation and was also compared with implanted rats early post-implantation (Base). Aldo and MI increased the AF substrate and atrial fibrosis. In the MI group only, AF duration was correlated with the level of atrial fibrosis and was inversely correlated with systolic function. Unexpectedly, Shams also developed progressive AF substrate relative to Base individuals. Further studies indicated that serum inflammatory markers (IL-6, TNF-alpha) were not elevated in the shams. In addition, we excluded anxiety\depression due to social-isolation as an AF promoting factor. Finally, enhanced biocompatibility of the atrial electrode did not inhibit the gradual development of AF substrate over a testing period of up to 8 weeks. Overall, we successfully validated the first system for long-term AF substrate testing in ambulatory rats.
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Egorov YV, Lang D, Tyan L, Turner D, Lim E, Piro ZD, Hernandez JJ, Lodin R, Wang R, Schmuck EG, Raval AN, Ralphe CJ, Kamp TJ, Rosenshtraukh LV, Glukhov AV. Caveolae-Mediated Activation of Mechanosensitive Chloride Channels in Pulmonary Veins Triggers Atrial Arrhythmogenesis. J Am Heart Assoc 2019; 8:e012748. [PMID: 31597508 PMCID: PMC6818041 DOI: 10.1161/jaha.119.012748] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Background Atrial fibrillation often occurs in the setting of hypertension and associated atrial dilation with pathologically increased cardiomyocyte stretch. In the setting of atrial dilation, mechanoelectric feedback has been linked to the development of ectopic beats that trigger paroxysmal atrial fibrillation mainly originating from pulmonary veins (PVs). However, the precise mechanisms remain poorly understood. Methods and Results We identify mechanosensitive, swelling‐activated chloride ion channels (ICl,swell) as a crucial component of the caveolar mechanosensitive complex in rat and human cardiomyocytes. In vitro optical mapping of rat PV, single rat PV, and human cardiomyocyte patch clamp studies showed that stretch‐induced activation of ICl,swell leads to membrane depolarization and decreased action potential amplitude, which trigger conduction discontinuities and both ectopic and reentrant activities within the PV. Reverse transcription quantitative polymerase chain reaction, immunofluorescence, and coimmunoprecipitation studies showed that ICl,swell likely consists of at least 2 components produced by mechanosensitive ClC‐3 (chloride channel‐3) and SWELL1 (also known as LRRC8A [leucine rich repeat containing protein 8A]) chloride channels, which form a macromolecular complex with caveolar scaffolding protein Cav3 (caveolin 3). Downregulation of Cav3 protein expression and disruption of caveolae structures during chronic hypertension in spontaneously hypertensive rats facilitates activation of ICl,swell and increases PV sensitivity to stretch 10‐ to 50‐fold, promoting the development of atrial fibrillation. Conclusions Our findings identify caveolae‐mediated activation of mechanosensitive ICl,swell as a critical cause of PV ectopic beats that can initiate atrial arrhythmias including atrial fibrillation. This mechanism is exacerbated in the setting of chronically elevated blood pressures.
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Affiliation(s)
- Yuriy V. Egorov
- Laboratory of Heart ElectrophysiologyCardiology Research CentreMoscowRussian Federation
| | - Di Lang
- Department of MedicineCardiovascular MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWI
| | - Leonid Tyan
- Department of MedicineCardiovascular MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWI
| | - Daniel Turner
- Department of MedicineCardiovascular MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWI
| | - Evi Lim
- Department of MedicineCardiovascular MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWI
| | - Zachary D. Piro
- Department of MedicineCardiovascular MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWI
| | - Jonathan J. Hernandez
- Department of MedicineCardiovascular MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWI
- Department of PediatricsPediatric CardiologyUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWI
| | - Rylie Lodin
- Department of MedicineCardiovascular MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWI
| | - Rose Wang
- Department of MedicineCardiovascular MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWI
| | - Eric G. Schmuck
- Department of MedicineCardiovascular MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWI
| | - Amish N. Raval
- Department of MedicineCardiovascular MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWI
| | - Carter J. Ralphe
- Department of PediatricsPediatric CardiologyUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWI
| | - Timothy J. Kamp
- Department of MedicineCardiovascular MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWI
| | | | - Alexey V. Glukhov
- Department of MedicineCardiovascular MedicineUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWI
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Abstract
Hypertension represents an autonomic dysfunction, characterized by increased sympathetic and decreased parasympathetic cardiovascular tone leading to resting tachycardia. Therefore, studies assessing hypertension-associated changes in isolated cardiac tissues were conducted under electric field stimulation to stimulate the neurons. Herein, we characterize the influence of the autonomic neurotransmitter on the baseline atrial chronotropism of unpaced isolated right atria of normotensive Wistar rats (NWR) and spontaneously hypertensive rats (SHR). Our results revealed a resting bradycardia in tissues from SHR in comparison to NWR. The release of autonomic neurotransmitters, acetylcholine or norepinephrine, still occurs in the electrically unstimulated right atrium, after excision of the sympathetic nerve, which could explain differences in basal heart rate between NWR and SHR. Nicotine and the acetylcholinesterase inhibitor physostigmine reduced the chronotropism of right atria from either NWR or SHR. Conversely, the muscarinic receptor antagonist atropine did not affect the basal chronotropism of tissues from both strains. Furthermore, tyramine increased the chronotropism of NWR and SHR atria indicating availability of the neuronal stocks of noradrenaline. Although the monoamine uptake inhibitor cocaine increased right atrium chronotropism in both strains, the basal heart rate was not affected by the β-adrenoceptor antagonist propranolol. In summary, after acute section of the sympathetic nerve, autonomic neurotransmitters are still released either in resting conditions or upon pharmacological stimulation of right atria from both strains. Nevertheless, autonomic neurotransmission does not affect resting chronotropism, nor is the responsible for reduced basal heart rate of the isolated right atrium of hypertensive rats.
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Verdecchia P, Angeli F, Reboldi G. Hypertension and Atrial Fibrillation: Doubts and Certainties From Basic and Clinical Studies. Circ Res 2019; 122:352-368. [PMID: 29348255 DOI: 10.1161/circresaha.117.311402] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Hypertension and atrial fibrillation (AF) are 2 important public health priorities. Their prevalence is increasing worldwide, and the 2 conditions often coexist in the same patient. Hypertension and AF are strikingly related to an excess risk of cardiovascular disease and death. Hypertension ultimately increases the risk of AF, and because of its high prevalence in the population, it accounts for more cases of AF than other risk factors. Among patients with established AF, hypertension is present in about 60% to 80% of individuals. Despite the well-known association between hypertension and AF, several pathogenetic mechanisms underlying the higher risk of AF in hypertensive patients are still incompletely known. From an epidemiological standpoint, it is unclear whether the increasing risk of AF with blood pressure (BP) is linear or threshold. It is uncertain whether an intensive control of BP or the use of specific antihypertensive drugs, such as those inhibiting the renin-angiotensin-aldosterone system, reduces the risk of subsequent AF in hypertensive patients in sinus rhythm. Finally, in spite of the observational evidence suggesting a progressive relation between BP levels and the risk of thromboembolism and bleeding in patients with hypertension and AF, the extent to which BP should be lowered in these patients, including those who undergo catheter ablation, remains uncertain. This article summarizes the main basic mechanisms through which hypertension is believed to promote AF. It also explores epidemiological data supporting an evolutionary pathway from hypertension to AF, including the emerging evidence favoring an intensive BP control or the use of drugs, which inhibit the renin-angiotensin-aldosterone system to reduce the risk of AF. Finally, it examines the impact of non-vitamin K antagonist oral anticoagulants compared with warfarin in relation to hypertension.
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Affiliation(s)
- Paolo Verdecchia
- From the Struttura Complessa di Medicina, Dipartimento di Medicina, Ospedale di Assisi, Italy (P.V.); and Struttura Complessa di Cardiologia e Fisiopatologia Cardiovascolare, Dipartimento di Cardiologia (F.A.) and Dipartimento di Medicina Interna (G.R.), Università di Perugia, Italy.
| | - Fabio Angeli
- From the Struttura Complessa di Medicina, Dipartimento di Medicina, Ospedale di Assisi, Italy (P.V.); and Struttura Complessa di Cardiologia e Fisiopatologia Cardiovascolare, Dipartimento di Cardiologia (F.A.) and Dipartimento di Medicina Interna (G.R.), Università di Perugia, Italy
| | - Gianpaolo Reboldi
- From the Struttura Complessa di Medicina, Dipartimento di Medicina, Ospedale di Assisi, Italy (P.V.); and Struttura Complessa di Cardiologia e Fisiopatologia Cardiovascolare, Dipartimento di Cardiologia (F.A.) and Dipartimento di Medicina Interna (G.R.), Università di Perugia, Italy
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25
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Fan B, Wang H, Wu T, Li Y, Lin Z, Li M, Li Q, Zhang W, Zheng Q. Electrophysiological Measurement of Rat Atrial Epicardium Using a Novel Stereotaxic Apparatus. Int Heart J 2019; 60:400-410. [DOI: 10.1536/ihj.18-215] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Boyuan Fan
- Department of Cardiology, The Second Affiliate Hospital of Xi'an Jiaotong University
| | - Hongtao Wang
- Department of Cardiology, The Second Affiliate Hospital of Xi'an Jiaotong University
| | - Tao Wu
- China Coal Xi'an Design Engineering Co., Ltd; Xi'an
| | - Yingqi Li
- Department of Cardiology, The Second Affiliate Hospital of Xi'an Jiaotong University
| | - Zehao Lin
- Department of Cardiology, The Second Affiliate Hospital of Xi'an Jiaotong University
| | - Mengying Li
- Department of Endocrinology, Xijing Hospital of the Fourth Military Medicine University
| | - Qing Li
- Department of Cardiology, The Second Affiliate Hospital of Xi'an Jiaotong University
| | - Wei Zhang
- Department of Pharmacy, Xijing Hospital of the Fourth Military Medicine University
| | - Qiangsun Zheng
- Department of Cardiology, The Second Affiliate Hospital of Xi'an Jiaotong University
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Ghebleh Zadeh N, Vaezi G, Bakhtiarian A, Mousavi Z, Shiravi A, Nikoui V. The potassium channel blocker, dalfampridine diminishes ouabain-induced arrhythmia in isolated rat atria. Arch Physiol Biochem 2019; 125:25-29. [PMID: 29390872 DOI: 10.1080/13813455.2018.1430158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The aim of the present experiment was to investigate the possible antiarrhythmic effects of dalfampridine in ouabain-induced arrhythmia in rats. Twenty-four male rats including the control and dalfampridine-incubated (100 µM to 10 mM) ouabain-stimulated (40 µM) groups were used. After induction of anesthesia, the atria were isolated and the time of onset of arrhythmia and asystole were recorded. The contractile force of atria was also measured. Dalfampridine at concentration of 1 mM significantly postponed the onset of arrhythmia and asystole compared to control group (p ≤ .05). Ouabain significantly increased the atrial beating rate in control group (p ≤ .05), while pretreatment of isolated atria with dalfampridine reversed this effect. Incubation of isolated atria with ouabain did not alter the contractile force in both control- and dalfampridine-treated groups (p > .05). It is concluded that dalfampridine might possess antiarrhythmic properties in reducing the atrial arrhythmias.
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Affiliation(s)
- Nahid Ghebleh Zadeh
- a Department of Biology, Damghan Branch , Islamic Azad University , Damghan , Iran
| | - Gholamhassan Vaezi
- a Department of Biology, Damghan Branch , Islamic Azad University , Damghan , Iran
| | - Azam Bakhtiarian
- b Department of Pharmacology, School of Medicine , Tehran University of Medical Sciences , Tehran , Iran
- c Experimental Medicine Research Center , Tehran University of Medical Sciences , Tehran , Iran
| | - Zahra Mousavi
- d Department of Pharmacology-Toxicology, Faculty of Pharmacy, Pharmaceutical Sciences Branch , Islamic Azad University (IAUPS) , Tehran , Iran
| | - Abdolhossein Shiravi
- a Department of Biology, Damghan Branch , Islamic Azad University , Damghan , Iran
| | - Vahid Nikoui
- e Razi Drug Research Center , Iran University of Medical Sciences , Tehran , Iran
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Roder F, Strotmann J, Fox H, Bitter T, Horstkotte D, Oldenburg O. Interactions of Sleep Apnea, the Autonomic Nervous System, and Its Impact on Cardiac Arrhythmias. CURRENT SLEEP MEDICINE REPORTS 2018. [DOI: 10.1007/s40675-018-0117-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Pulmonary vein remodeling in hypertension: Mechanistic insight into primary prevention of atrial fibrillation. Anatol J Cardiol 2018. [PMID: 29521310 PMCID: PMC5864766 DOI: 10.14744/anatoljcardiol.2017.25931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Electrical and histological remodeling of the pulmonary vein in 2K1C hypertensive rats: Indication of initiation and maintenance of atrial fibrillation. Anatol J Cardiol 2018; 19:169-175. [PMID: 29339676 PMCID: PMC5864765 DOI: 10.14744/anatoljcardiol.2017.7844] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Objective Hypertension is a significant risk factor for atrial fibrillation (AF). The role of pulmonary vein (PV) remodeling in the mechanistic association between hypertension and AF is not definitive. In this study, we aimed to identify changes in the electrophysiology and histology in PVs in two-kidney, one-clip (2K1C) hypertensive rats. Methods Fifty male Sprague-Dawley rats were classified into the 2K1C and sham-operated groups. The systolic blood pressure was measured every 2 weeks. The left atrial diameter was measured by transthoracic echocardiography. Left superior PV (LSPV) and left atrial (LA) fibrosis was evaluated by Masson’s trichrome staining. The expression of fibrosis markers [angiotensin II (Ang II), transforming growth factor-β1 (TGF-β1), matrix metalloproteinase-2 (MMP-2), and collagen I (Col I)] and ion channels [Kir2.1, Kir2.3, Cav1.2, and Nav1.5] in LSVP was quantified by western blot. Conventional microelectrodes were used to record the action potential duration at 90% repolarization (APD90) and effective refractory period (ERP) in isolated LA. Results At 4 months, the 2K1C hypertensive rats developed LA dilation. Col deposition in LSPV and left atrium and expression of TGF-β1, MMP-2, and Col I in LSPV were significantly increased in 2K1C hypertensive rats. In addition, hypertension reduced the expression of Nav1.5 and Kir2.1, although there were no significant differences in APD90; ERP; and expression of Ang II, Kir2.3, and Cav1.2 between the two groups. Conclusion Hypertension may lead to changes in the electrophysiology and histology of rats PVs, which is characterized by significant reduction in the expression of Nav1.5 and Kir2.1 and increase in interstitial fibrosis. These observations may clarify the role of PVs in the mechanistic association between hypertension and AF.
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30
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Pluteanu F, Nikonova Y, Holzapfel A, Herzog B, Scherer A, Preisenberger J, Plačkić J, Scheer K, Ivanova T, Bukowska A, Goette A, Kockskämper J. Progressive impairment of atrial myocyte function during left ventricular hypertrophy and heart failure. J Mol Cell Cardiol 2018; 114:253-263. [DOI: 10.1016/j.yjmcc.2017.11.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 10/22/2017] [Accepted: 11/27/2017] [Indexed: 12/29/2022]
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Thanigaimani S, McLennan E, Linz D, Mahajan R, Agbaedeng TA, Lee G, Kalman JM, Sanders P, Lau DH. Progression and reversibility of stretch induced atrial remodeling: Characterization and clinical implications. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2017; 130:376-386. [PMID: 28734850 DOI: 10.1016/j.pbiomolbio.2017.07.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 07/17/2017] [Accepted: 07/18/2017] [Indexed: 12/13/2022]
Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia and across the developed nations, it contributes to increasing hospitalizations and healthcare burden. Several comorbidities and risk factors including hypertension, heart failure, obstructive sleep apnoea and obesity are known to play an important role in the initiation and perpetuation of AF and atrial stretch or dilatation may play a central mechanistic role. The impact of atrial stretch in the development of AF can vary dependent on the underlying disease. This review focuses on understanding the substrate for AF in conditions of acute and chronic stretch and in the presence of common co-morbidities or risk factors through the review of findings in both animal and human studies. Additionally, the reversibility of atrial remodeling following stretch release will also be discussed. Identification of clinical conditions associated with increased atrial stretch as well as the treatment or prevention of these conditions may help to prevent AF progression and improve sinus rhythm maintenance.
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Affiliation(s)
- Shivshankar Thanigaimani
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Emma McLennan
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Dominik Linz
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Rajiv Mahajan
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Thomas A Agbaedeng
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Geoffrey Lee
- Department of Cardiology, Royal Melbourne Hospital and Department of Medicine, The University of Melbourne, Melbourne, Victoria, Australia
| | - Jonathan M Kalman
- Department of Cardiology, Royal Melbourne Hospital and Department of Medicine, The University of Melbourne, Melbourne, Victoria, Australia
| | - Prashanthan Sanders
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Dennis H Lau
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, South Australia, Australia.
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Doñate Puertas R, Meugnier E, Romestaing C, Rey C, Morel E, Lachuer J, Gadot N, Scridon A, Julien C, Tronc F, Chapuis B, Valla C, Janin A, Pirola L, Méjat A, Rome S, Chevalier P. Atrial fibrillation is associated with hypermethylation in human left atrium, and treatment with decitabine reduces atrial tachyarrhythmias in spontaneously hypertensive rats. Transl Res 2017; 184:57-67.e5. [PMID: 28427903 DOI: 10.1016/j.trsl.2017.03.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 03/13/2017] [Accepted: 03/17/2017] [Indexed: 10/19/2022]
Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia. As the molecular mechanisms underlying the pathology are largely unknown, this cardiac arrhythmia remains difficult to treat. To identify specific molecular actors involved in AF, we have performed a transcriptomic analysis on left atrium (LA) from patients with valvular heart disease with or without AF. We showed that 1627 genes had altered basal expression level in LA tissue of AF patients compared with the control group. The significantly enriched gene ontology biological process "anatomical structure morphogenesis" contained the highest number of genes in line with changes in structure that occur when the human heart remodels following AF development (ie, LA dilatation and interstitial fibrosis). We then focused the study on Pitx2 (paired-like homeodomain 2), being the most altered transcription factor in LA from AF patients and from which compelling evidence have indicated that its reduced expression can be considered as a marker for the disease. In addition, its expression was inversely correlated with LA size. We demonstrated that AF is associated with Pitx2 promoter hypermethylation both in humans and arrhythmic aging spontaneously hypertensive rats. Chronic administration of a DNA methylation inhibitor (ie, 5-Aza-2'-deoxycitidine) improved ECG arrhythmic profiles and superoxide dismutase activities and reduced fibrosis in the left ventricle of spontaneously hypertensive rats. Taken together, these data support the notion that AF is associated with epigenetic changes in LA and provide a proof-of-concept that hypomethylating agents have to be considered in the treatment of atrial arrhythmias.
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Affiliation(s)
| | - E Meugnier
- CarMeN Laboratory (UMR INSERM 1060-INRA 1397, INSA), Lyon-Sud Faculty of Medicine, University of Lyon, Pierre-Bénite, France
| | - C Romestaing
- LEHNA Laboratory, CNRS, UMR 5023, University of Lyon, Villeurbanne, France
| | - C Rey
- ProfilXpert, UNIV-US7 INSERM-UMS 3453 CNRS, Lyon, France
| | - E Morel
- Rhythmology Unit, Louis Pradel Cardiology Hospital, Hospices Civils de Lyon, Bron, France
| | - J Lachuer
- ProfilXpert, UNIV-US7 INSERM-UMS 3453 CNRS, Lyon, France
| | - N Gadot
- Plateform Anipath, Laënnec Faculty of Medecine, University of Lyon, Lyon, France
| | - A Scridon
- Physiology Department, University of Medicine and Pharmacy of Tîrgu Mures, Tîrgu Mures, Romania
| | - C Julien
- EA 4612 Neurocardiology unit, University of Lyon, Lyon, France
| | - F Tronc
- Pneumology Unit, Louis Pradel Cardiology Hospital, Hospices Civils de Lyon, Bron, France
| | - B Chapuis
- EA 4612 Neurocardiology unit, University of Lyon, Lyon, France
| | - C Valla
- Institut NeuroMyoGene (INMG), UMR CNRS 5310-INSERM U1217 / University of Lyon, Lyon, France
| | - A Janin
- Institut NeuroMyoGene (INMG), UMR CNRS 5310-INSERM U1217 / University of Lyon, Lyon, France
| | - L Pirola
- CarMeN Laboratory (UMR INSERM 1060-INRA 1397, INSA), Lyon-Sud Faculty of Medicine, University of Lyon, Pierre-Bénite, France
| | - A Méjat
- Institut NeuroMyoGene (INMG), UMR CNRS 5310-INSERM U1217 / University of Lyon, Lyon, France
| | - S Rome
- CarMeN Laboratory (UMR INSERM 1060-INRA 1397, INSA), Lyon-Sud Faculty of Medicine, University of Lyon, Pierre-Bénite, France
| | - Philippe Chevalier
- EA 4612 Neurocardiology unit, University of Lyon, Lyon, France; Rhythmology Unit, Louis Pradel Cardiology Hospital, Hospices Civils de Lyon, Bron, France.
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Thanigaimani S, Lau DH, Agbaedeng T, Elliott AD, Mahajan R, Sanders P. Molecular mechanisms of atrial fibrosis: implications for the clinic. Expert Rev Cardiovasc Ther 2017; 15:247-256. [DOI: 10.1080/14779072.2017.1299005] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Shivshankar Thanigaimani
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
| | - Dennis H Lau
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
| | - Thomas Agbaedeng
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
| | - Adrian D. Elliott
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
| | - Rajiv Mahajan
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
| | - Prashanthan Sanders
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
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Bond RC, Bryant SM, Watson JJ, Hancox JC, Orchard CH, James AF. Reduced density and altered regulation of rat atrial L-type Ca 2+ current in heart failure. Am J Physiol Heart Circ Physiol 2017; 312:H384-H391. [PMID: 27923791 PMCID: PMC5402008 DOI: 10.1152/ajpheart.00528.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 11/21/2016] [Accepted: 11/23/2016] [Indexed: 11/22/2022]
Abstract
Constitutive regulation by PKA has recently been shown to contribute to L-type Ca2+ current (ICaL) at the ventricular t-tubule in heart failure. Conversely, reduction in constitutive regulation by PKA has been proposed to underlie the downregulation of atrial ICaL in heart failure. The hypothesis that downregulation of atrial ICaL in heart failure involves reduced channel phosphorylation was examined. Anesthetized adult male Wistar rats underwent surgical coronary artery ligation (CAL, N=10) or equivalent sham-operation (Sham, N=12). Left atrial myocytes were isolated ~18 wk postsurgery and whole cell currents recorded (holding potential=-80 mV). ICaL activated by depolarizing pulses to voltages from -40 to +50 mV were normalized to cell capacitance and current density-voltage relations plotted. CAL cell capacitances were ~1.67-fold greater than Sham (P ≤ 0.0001). Maximal ICaL conductance (Gmax ) was downregulated more than 2-fold in CAL vs. Sham myocytes (P < 0.0001). Norepinephrine (1 μmol/l) increased Gmax >50% more effectively in CAL than in Sham so that differences in ICaL density were abolished. Differences between CAL and Sham Gmax were not abolished by calyculin A (100 nmol/l), suggesting that increased protein dephosphorylation did not account for ICaL downregulation. Treatment with either H-89 (10 μmol/l) or AIP (5 μmol/l) had no effect on basal currents in Sham or CAL myocytes, indicating that, in contrast to ventricular myocytes, neither PKA nor CaMKII regulated basal ICaL Expression of the L-type α1C-subunit, protein phosphatases 1 and 2A, and inhibitor-1 proteins was unchanged. In conclusion, reduction in PKA-dependent regulation did not contribute to downregulation of atrial ICaL in heart failure.NEW & NOTEWORTHY Whole cell recording of L-type Ca2+ currents in atrial myocytes from rat hearts subjected to coronary artery ligation compared with those from sham-operated controls reveals marked reduction in current density in heart failure without change in channel subunit expression and associated with altered phosphorylation independent of protein kinase A.
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Affiliation(s)
- Richard C Bond
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Simon M Bryant
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Judy J Watson
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Jules C Hancox
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Clive H Orchard
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Andrew F James
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
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35
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Carillon J, Gauthier A, Barial S, Tournier M, Gayrard N, Lajoix AD, Jover B. Relaxin and atrial natriuretic peptide pathways participate in the anti-fibrotic effect of a melon concentrate in spontaneously hypertensive rats. Food Nutr Res 2016; 60:30985. [PMID: 27079780 PMCID: PMC4832218 DOI: 10.3402/fnr.v60.30985] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/04/2016] [Accepted: 03/17/2016] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND In spontaneously hypertensive rats (SHR), a model of human essential hypertension, oxidative stress is involved in the development of cardiac hypertrophy and fibrosis associated with hypertension. Dietary supplementation with agents exhibiting antioxidant properties could have a beneficial effect in remodeling of the heart. We previously demonstrated a potent anti-hypertrophic effect of a specific melon (Cucumis melo L.) concentrate with antioxidant properties in spontaneously hypertensive rats. Relaxin and atrial natriuretic peptide (ANP) were reported to reduce collagen deposition and fibrosis progression in various experimental models. OBJECTIVE The aim of the present investigation was to test the hypothesis that, beside reduction in oxidative stress, the melon concentrate may act through relaxin, its receptor (relaxin/insulin-like family peptide receptor 1, RXFP1), and ANP in SHR. DESIGN AND RESULTS The melon concentrate, given orally during 4 days, reduced cardiomyocyte size (by 25%) and totally reversed cardiac collagen content (Sirius red staining) in SHR but not in their normotensive controls. Treatment with the melon concentrate lowered cardiac nitrotyrosine-stained area (by 45%) and increased by 17-19% the cardiac expression (Western blot) of superoxide dismutase (SOD) and glutathione peroxidase. In addition, plasma relaxin concentration was normalized while cardiac relaxin (Western blot) was lowered in treated SHR. Cardiac relaxin receptor level determined by immunohistochemical analysis increased only in treated SHR. Similarly, the melon concentrate reversed the reduction of plasma ANP concentration and lowered its cardiac expression. CONCLUSIONS The present results demonstrate that reversal of cardiac fibrosis by the melon concentrate involves antioxidant defenses, as well as relaxin and ANP pathways restoration. It is suggested that dietary SOD supplementation could be a useful additional strategy against cardiac hypertrophy and fibrosis.
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Affiliation(s)
- Julie Carillon
- EA7288 Université de Montpellier, Montpellier, France.,Bionov Research, Montpellier, France
| | | | - Sandy Barial
- EA7288 Université de Montpellier, Montpellier, France
| | | | | | | | - Bernard Jover
- EA7288 Université de Montpellier, Montpellier, France;
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Linz D, Linz B, Hohl M, Böhm M. Atrial arrhythmogenesis in obstructive sleep apnea: Therapeutic implications. Sleep Med Rev 2016; 26:87-94. [DOI: 10.1016/j.smrv.2015.03.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Revised: 03/18/2015] [Accepted: 03/25/2015] [Indexed: 10/23/2022]
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Pellman J, Sheikh F. Atrial fibrillation: mechanisms, therapeutics, and future directions. Compr Physiol 2016; 5:649-65. [PMID: 25880508 DOI: 10.1002/cphy.c140047] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia, affecting 1% to 2% of the general population. It is characterized by rapid and disorganized atrial activation leading to impaired atrial function, which can be diagnosed on an EKG by lack of a P-wave and irregular QRS complexes. AF is associated with increased morbidity and mortality and is a risk factor for embolic stroke and worsening heart failure. Current research on AF support and explore the hypothesis that initiation and maintenance of AF require pathophysiological remodeling of the atria, either specifically as in lone AF or secondary to other heart disease as in heart failure-associated AF. Remodeling in AF can be grouped into three categories that include: (i) electrical remodeling, which includes modulation of L-type Ca(2+) current, various K(+) currents and gap junction function; (ii) structural remodeling, which includes changes in tissues properties, size, and ultrastructure; and (iii) autonomic remodeling, including altered sympathovagal activity and hyperinnervation. Electrical, structural, and autonomic remodeling all contribute to creating an AF-prone substrate which is able to produce AF-associated electrical phenomena including a rapidly firing focus, complex multiple reentrant circuit or rotors. Although various remodeling events occur in AF, current AF therapies focus on ventricular rate and rhythm control strategies using pharmacotherapy and surgical interventions. Recent progress in the field has started to focus on the underlying substrate that drives and maintains AF (termed upstream therapies); however, much work is needed in this area. Here, we review current knowledge of AF mechanisms, therapies, and new areas of investigation.
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Affiliation(s)
- Jason Pellman
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
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39
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Zhang H, Cannell MB, Kim SJ, Watson JJ, Norman R, Calaghan SC, Orchard CH, James AF. Cellular Hypertrophy and Increased Susceptibility to Spontaneous Calcium-Release of Rat Left Atrial Myocytes Due to Elevated Afterload. PLoS One 2015; 10:e0144309. [PMID: 26713852 PMCID: PMC4694654 DOI: 10.1371/journal.pone.0144309] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 11/16/2015] [Indexed: 11/19/2022] Open
Abstract
Atrial remodeling due to elevated arterial pressure predisposes the heart to atrial fibrillation (AF). Although abnormal sarcoplasmic reticulum (SR) function has been associated with AF, there is little information on the effects of elevated afterload on atrial Ca2+-handling. We investigated the effects of ascending aortic banding (AoB) on Ca2+-handling in rat isolated atrial myocytes in comparison to age-matched sham-operated animals (Sham). Myocytes were either labelled for ryanodine receptor (RyR) or loaded with fluo-3-AM and imaged by confocal microscopy. AoB myocytes were hypertrophied in comparison to Sham controls (P<0.0001). RyR labeling was localized to the z-lines and to the cell edge. There were no differences between AoB and Sham in the intensity or pattern of RyR-staining. In both AoB and Sham, electrical stimulation evoked robust SR Ca2+-release at the cell edge whereas Ca2+ transients at the cell center were much smaller. Western blotting showed a decreased L-type Ca channel expression but no significant changes in RyR or RyR phosphorylation or in expression of Na+/Ca2+ exchanger, SR Ca2+ ATPase or phospholamban. Mathematical modeling indicated that [Ca2+]i transients at the cell center were accounted for by simple centripetal diffusion of Ca2+ released at the cell edge. In contrast, caffeine (10 mM) induced Ca2+ release was uniform across the cell. The caffeine-induced transient was smaller in AoB than in Sham, suggesting a reduced SR Ca2+-load in hypertrophied cells. There were no significant differences between AoB and Sham cells in the rate of Ca2+ extrusion during recovery of electrically-stimulated or caffeine-induced transients. The incidence and frequency of spontaneous Ca2+-transients following rapid-pacing (4 Hz) was greater in AoB than in Sham myocytes. In conclusion, elevated afterload causes cellular hypertrophy and remodeling of atrial SR Ca2+-release.
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Affiliation(s)
- Haifei Zhang
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Mark B. Cannell
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Shang Jin Kim
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Judy J. Watson
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Ruth Norman
- School of Biomedical Sciences, Garstang, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Sarah C. Calaghan
- School of Biomedical Sciences, Garstang, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Clive H. Orchard
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Andrew F. James
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
- * E-mail:
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40
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Iwasaki YK, Yamashita T, Sekiguchi A, Hayami N, Shimizu W. Importance of Pulmonary Vein Preferential Fibrosis for Atrial Fibrillation Promotion in Hypertensive Rat Hearts. Can J Cardiol 2015; 32:767-76. [PMID: 26875015 DOI: 10.1016/j.cjca.2015.09.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 09/04/2015] [Accepted: 09/06/2015] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND Hypertension is one of the independent risk factors for atrial fibrillation (AF). Pulmonary veins (PVs) play an important role as the substrate for AF and triggers of AF. The purpose of this study was to determine the structural remodelling of the PVs and its effect on promoting AF in hypertensive (HT) rat hearts. METHODS Eighteen-week-old Dahl salt-sensitive HT rats and their controls were used for histological and immunohistological analyses, and electrophysiological studies were performed in Langendorff perfused hearts. RESULTS Masson-trichrome staining revealed that hypertension significantly increased the fibrosis in the PVs, particularly in subendocardial and perivascular areas, compared with that in control rats, however, at this early stage of hypertension, left atrial fibrosis was not prominent. In the HT rat hearts with PVs, electrical stimulation significantly increased the number of repetitive atrial firing and atrial tachycardia inducibility, which significantly diminished after the excision of the PVs. An immunofluorescent analysis revealed that HT rats had PV specific endocardial smooth muscle actin (αSMA)-positive cells with remarkable proliferation of platelet-derived growth factor (PDGF)-C and vascular endothelial growth factor (VEGF), which was lacking in the left atrial structures of the control and the HT rats. Pretreatment with imatinib, a PDGF receptor activity blocker, in HT rats reduced the αSMA-positive cell proliferation and fibrosis in the PVs and also induced a significant reduction in VEGF expression. Also, the drug pretreatment effectively prevented repetitive atrial firing promotion without affecting the blood pressure. CONCLUSIONS PV preferential fibrosis might play an important role in the arrhythmogenic substrate of AF in HT rat hearts.
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Affiliation(s)
- Yu-Ki Iwasaki
- The Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan.
| | | | | | - Noriyuki Hayami
- The 4th Department of Internal Medicine, Teikyo University School of Medicine, Kanagawa, Japan
| | - Wataru Shimizu
- The Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
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Ruiz M, Gélinas R, Vaillant F, Lauzier B, Des Rosiers C. Metabolic Tracing Using Stable Isotope-Labeled Substrates and Mass Spectrometry in the Perfused Mouse Heart. Methods Enzymol 2015; 561:107-47. [PMID: 26358903 DOI: 10.1016/bs.mie.2015.06.026] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
There has been a resurgence of interest for the field of cardiac metabolism catalyzed by evidence demonstrating a role of metabolic dysregulation in the pathogenesis of heart disease as well as the increased need for new therapeutic targets for patients with these diseases. In this regard, measuring substrate fluxes is critical in providing insight into the dynamics of cellular metabolism and in delineating the regulation of metabolite production and utilization. This chapter provides a comprehensive description of concepts, guidelines, and tips to assess metabolic fluxes relevant to energy substrate metabolism using (13)C-labeled substrates and (13)C-isotopomer analysis by gas chromatography-mass spectrometry (GC-MS), and the ex vivo working heart as study model. The focus will be on the mouse and on flux parameters, which are commonly assessed in the field, namely, those relevant to substrate selection for energy metabolism, specifically the relative contribution of carbohydrate (glucose, lactate, and pyruvate) and fatty acid oxidation to acetyl-CoA formation for citrate synthesis, glycolysis, as well as anaplerosis. We provide detailed procedures for the heart isolation and perfusion in the working mode as well as for sample processing for metabolite extraction and analysis by GC-MS and subsequent data processing for calculation of metabolic flux parameters. Finally, we address practical considerations and discuss additional applications and future challenges.
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Affiliation(s)
- Matthieu Ruiz
- Department of Nutrition, Université de Montréal, Montreal, Quebec, Canada; Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada
| | - Roselle Gélinas
- Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada; Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Fanny Vaillant
- IHU Institut de Rythmologie et Modélisation Cardiaque, Fondation Bordeaux, Université de Bordeaux, Bordeaux, France; Inserm U1045 Centre de Recherche Cardio-Thoracique de Bordeaux, Université de Bordeaux, Bordeaux, France
| | | | - Christine Des Rosiers
- Department of Nutrition, Université de Montréal, Montreal, Quebec, Canada; Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada; Department of Medicine, Université de Montréal, Montreal, Quebec, Canada.
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42
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Triggers, Substrate, and Hypertension in Atrial Fibrillation. JACC Clin Electrophysiol 2015; 1:174-176. [DOI: 10.1016/j.jacep.2015.05.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 05/11/2015] [Accepted: 05/11/2015] [Indexed: 11/23/2022]
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43
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Obesity and atrial fibrillation: A comprehensive review of the pathophysiological mechanisms and links. J Cardiol 2015; 66:361-9. [PMID: 25959929 DOI: 10.1016/j.jjcc.2015.04.002] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Revised: 03/15/2015] [Accepted: 04/02/2015] [Indexed: 12/15/2022]
Abstract
Obesity is a worldwide health problem with epidemic proportions that has been associated with atrial fibrillation (AF). Even though the underlying pathophysiological mechanisms have not been completely elucidated, several experimental and clinical studies implicate obesity in the initiation and perpetuation of AF. Of note, hypertension, diabetes mellitus, metabolic syndrome, coronary artery disease, and obstructive sleep apnea, represent clinical correlates between obesity and AF. In addition, ventricular adaptation, diastolic dysfunction, and epicardial adipose tissue appear to be implicated in atrial electrical and structural remodeling, thereby promoting the arrhythmia in obese subjects. The present article provides a concise overview of the association between obesity and AF, and highlights the underlying pathophysiological mechanisms.
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44
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Wang WW, Zhang FL, Chen JH, Chen XH, Fu FY, Tang MR, Chen LL. Telmisartan reduces atrial arrhythmia susceptibility through the regulation of RAS-ERK and PI3K-Akt-eNOS pathways in spontaneously hypertensive rats. Can J Physiol Pharmacol 2015; 93:657-65. [PMID: 26158699 DOI: 10.1139/cjpp-2014-0416] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Telmisartan is an angiotensin II receptor blocker that displays unique PPAR-γ modulating activity. PPAR-γ agonists have been shown to decrease susceptibility to atrial fibrillation through their antioxidant and antiapoptotic effects. The aim of this study was to determine whether telmisartan would have a greater effect on susceptibility to atrial arrhythmia in a hypertensive rat model than valsartan, which is a traditional angiotensin II receptor blocker. In this study, spontaneously hypertensive rats were treated with 10 mg·(kg body mass)(-1)·d(-1) telmisartan (TEL group), 10 mg·(kg body mass)(-1)·d(-1) valsartan (VAL group), or vehicle (saline; SHR group) for 4 weeks. Age-matched Wistar-Kyoto rats (WKY) were used as normotensive controls. After 4 weeks of treatment, we performed echocardiographic assessment, electrophysiological analysis, histological evaluation, and Western blot analysis. Telmisartan decreased systolic blood pressure to a similar extent as valsartan. Relative to the WKY controls, atrial arrhythmia susceptibility was significantly increased in the SHR group, and was significantly decreased by both telmisartan and valsartan, albeit to a greater extent with telmisartan. Arrhythmogenic atrial remodeling, including enlargement of the left atrium, myocyte hypertrophy, interstitial fibrosis, and myocyte apoptosis, was observed in the SHR group, and was accompanied by activated RAS-ERK signaling and suppressed PI3K-Akt-eNOS signaling. The results suggest that telmisartan reduced susceptibility to atrial arrhythmia to a greater extent than valsartan, ameliorated atrial remodeling, and reversed imbalances in the RAS-ERK and PI3K-Akt-eNOS pathways.
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Affiliation(s)
- Wei-Wei Wang
- Department of Coronary Artery Disease, Union Hospital, Union Clinic Medical College, Fujian Medical University, 29 Xin-Quan Road, Fuzhou 350001, China.,Department of Coronary Artery Disease, Union Hospital, Union Clinic Medical College, Fujian Medical University, 29 Xin-Quan Road, Fuzhou 350001, China
| | - Fei-Long Zhang
- Department of Coronary Artery Disease, Union Hospital, Union Clinic Medical College, Fujian Medical University, 29 Xin-Quan Road, Fuzhou 350001, China.,Department of Coronary Artery Disease, Union Hospital, Union Clinic Medical College, Fujian Medical University, 29 Xin-Quan Road, Fuzhou 350001, China
| | - Jian-Hua Chen
- Department of Coronary Artery Disease, Union Hospital, Union Clinic Medical College, Fujian Medical University, 29 Xin-Quan Road, Fuzhou 350001, China.,Department of Coronary Artery Disease, Union Hospital, Union Clinic Medical College, Fujian Medical University, 29 Xin-Quan Road, Fuzhou 350001, China
| | - Xue-Hai Chen
- Department of Coronary Artery Disease, Union Hospital, Union Clinic Medical College, Fujian Medical University, 29 Xin-Quan Road, Fuzhou 350001, China.,Department of Coronary Artery Disease, Union Hospital, Union Clinic Medical College, Fujian Medical University, 29 Xin-Quan Road, Fuzhou 350001, China
| | - Fa-Yuan Fu
- Department of Coronary Artery Disease, Union Hospital, Union Clinic Medical College, Fujian Medical University, 29 Xin-Quan Road, Fuzhou 350001, China.,Department of Coronary Artery Disease, Union Hospital, Union Clinic Medical College, Fujian Medical University, 29 Xin-Quan Road, Fuzhou 350001, China
| | - Mi-Rong Tang
- Department of Coronary Artery Disease, Union Hospital, Union Clinic Medical College, Fujian Medical University, 29 Xin-Quan Road, Fuzhou 350001, China.,Department of Coronary Artery Disease, Union Hospital, Union Clinic Medical College, Fujian Medical University, 29 Xin-Quan Road, Fuzhou 350001, China
| | - Liang-Long Chen
- Department of Coronary Artery Disease, Union Hospital, Union Clinic Medical College, Fujian Medical University, 29 Xin-Quan Road, Fuzhou 350001, China.,Department of Coronary Artery Disease, Union Hospital, Union Clinic Medical College, Fujian Medical University, 29 Xin-Quan Road, Fuzhou 350001, China
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Pluteanu F, Heß J, Plackic J, Nikonova Y, Preisenberger J, Bukowska A, Schotten U, Rinne A, Kienitz MC, Schäfer MKH, Weihe E, Goette A, Kockskämper J. Early subcellular Ca2+ remodelling and increased propensity for Ca2+ alternans in left atrial myocytes from hypertensive rats. Cardiovasc Res 2015; 106:87-97. [PMID: 25691541 DOI: 10.1093/cvr/cvv045] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
AIMS Hypertension is a major risk factor for atrial fibrillation. We hypothesized that arterial hypertension would alter atrial myocyte calcium (Ca2+) handling and that these alterations would serve to trigger atrial tachyarrhythmias. METHODS AND RESULTS Left atria or left atrial (LA) myocytes were isolated from spontaneously hypertensive rats (SHR) or normotensive Wistar-Kyoto (WKY) controls. Early after the onset of hypertension, at 3 months of age, there were no differences in Ca2+ transients (CaTs) or expression and phosphorylation of Ca2+ handling proteins between SHR and WKY. At 7 months of age, when left ventricular (LV) hypertrophy had progressed and markers of fibrosis were increased in left atrium, CaTs (at 1 Hz stimulation) were still unchanged. Subcellular alterations in Ca2+ handling were observed, however, in SHR atrial myocytes including (i) reduced expression of the α1C subunit of and reduced Ca2+ influx through L-type Ca2+ channels, (ii) reduced expression of ryanodine receptors with increased phosphorylation at Ser2808, (iii) decreased activity of the Na+ / Ca2+ exchanger (at unaltered intracellular Na+ concentration), and (iv) increased SR Ca2+ load with reduced fractional release. These changes were associated with an increased propensity of SHR atrial myocytes to develop frequency-dependent, arrhythmogenic Ca2+ alternans. CONCLUSIONS In SHR, hypertension induces early subcellular LA myocyte Ca2+ remodelling during compensated LV hypertrophy. In basal conditions, atrial myocyte CaTs are not changed. At increased stimulation frequency, however, SHR atrial myocytes become more prone to arrhythmogenic Ca2+ alternans, suggesting a link between hypertension, atrial Ca2+ homeostasis, and development of atrial tachyarrhythmias.
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Affiliation(s)
- Florentina Pluteanu
- Institute of Pharmacology and Clinical Pharmacy, Biochemical and Pharmacological Center (BPC) Marburg, Philipps-University Marburg, Karl-von-Frisch-Str. 1, 35032 Marburg, Germany
| | - Johannes Heß
- Institute of Pharmacology and Clinical Pharmacy, Biochemical and Pharmacological Center (BPC) Marburg, Philipps-University Marburg, Karl-von-Frisch-Str. 1, 35032 Marburg, Germany
| | - Jelena Plackic
- Institute of Pharmacology and Clinical Pharmacy, Biochemical and Pharmacological Center (BPC) Marburg, Philipps-University Marburg, Karl-von-Frisch-Str. 1, 35032 Marburg, Germany
| | - Yulia Nikonova
- Institute of Pharmacology and Clinical Pharmacy, Biochemical and Pharmacological Center (BPC) Marburg, Philipps-University Marburg, Karl-von-Frisch-Str. 1, 35032 Marburg, Germany
| | - Judit Preisenberger
- Institute of Pharmacology and Clinical Pharmacy, Biochemical and Pharmacological Center (BPC) Marburg, Philipps-University Marburg, Karl-von-Frisch-Str. 1, 35032 Marburg, Germany
| | - Alicja Bukowska
- Working Group of Molecular Electrophysiology, Medical Faculty, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Ulrich Schotten
- Department of Physiology, Cardiovascular Research Institute Maastricht, University Maastricht, Maastricht, The Netherlands
| | - Andreas Rinne
- Institute of Physiology, Ruhr-University Bochum, Bochum, Germany
| | | | - Martin K-H Schäfer
- Institute of Anatomy and Cell Biology, Philipps-University Marburg, Marburg, Germany
| | - Eberhard Weihe
- Institute of Anatomy and Cell Biology, Philipps-University Marburg, Marburg, Germany
| | - Andreas Goette
- Working Group of Molecular Electrophysiology, Medical Faculty, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany St. Vincenz-Hospital, Paderborn, Germany
| | - Jens Kockskämper
- Institute of Pharmacology and Clinical Pharmacy, Biochemical and Pharmacological Center (BPC) Marburg, Philipps-University Marburg, Karl-von-Frisch-Str. 1, 35032 Marburg, Germany
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Choisy SC, Kim SJ, Hancox JC, Jones SA, James AF. Effects of candesartan, an angiotensin II receptor type I blocker, on atrial remodeling in spontaneously hypertensive rats. Physiol Rep 2015; 3:3/1/e12274. [PMID: 25626873 PMCID: PMC4387744 DOI: 10.14814/phy2.12274] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Hypertension‐induced structural remodeling of the left atrium (LA) has been suggested to involve the renin–angiotensin system. This study investigated whether treatment with an angiotensin receptor blocker, candesartan, regresses atrial remodeling in spontaneously hypertensive rats (SHR). Effects of treatment with candesartan were compared to treatment with a nonspecific vasodilatator, hydralazine. Thirty to 32‐week‐old adult male SHR were either untreated (n = 15) or received one of either candesartan cilexetil (n = 9; 3 mg/kg/day) or hydralazine (n = 10; 14 mg/kg/day) via their drinking water for 14 weeks prior to experiments. Untreated age‐ and sex‐matched Wistar‐Kyoto rats (WKY; n = 13) represented a normotensive control group. Untreated SHR were hypertensive, with left ventricular hypertrophy (LVH) compared to WKY, but there were no differences in systolic pressures in excised, perfused hearts. LA from SHR were hypertrophied and showed increased fibrosis compared to those from WKY, but there was no change in connexin‐43 expression or phosphorylation. Treatment with candesartan reduced systolic tail artery pressures of conscious SHR below those of normotensive WKY and caused regression of both LVH and LA hypertrophy. Although hydralazine reduced SHR arterial pressures to those of WKY and led to regression of LA hypertrophy, it had no significant effect on LVH. Notably, LA fibrosis was unaffected by treatment with either agent. These data show that candesartan, at a dose sufficient to reduce blood pressure and LVH, did not cause regression of LA fibrosis in hypertensive rats. On the other hand, the data also suggest that normalization of arterial pressure can lead to the regression of LA hypertrophy. Structural remodeling of the atria, involving atria enlargement and fibrosis, in hypertension increases the risk of atrial fibrillation (AF). Treatment of spontaneously hypertensive rats with the angiotensin receptor blocker, candesartan, reduced arterial pressure and myocardial hypertrophy to the level of normotensive rats but had no effect on atrial fibrosis. The resistance of hypertension‐associated atrial fibrosis to the AT1 receptor antagonist may provide insight into the basis to the ineffectiveness of drugs targeting the renin–angiotensin system in reducing incidence of AF in hypertensive patients.
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Affiliation(s)
- Stéphanie C Choisy
- Cardiovascular Research Laboratories, School of Physiology & Pharmacology, School of Medical Sciences, University of Bristol, Bristol, U.K
| | - Shang-Jin Kim
- Department of Pharmacology and Toxicology, College of Veterinary Medicine, Chonbuk National University, Jeonju-City, South Korea
| | - Jules C Hancox
- Cardiovascular Research Laboratories, School of Physiology & Pharmacology, School of Medical Sciences, University of Bristol, Bristol, U.K
| | - Sandra A Jones
- School of Biological, Biomedical and Environmental Sciences, University of Hull, Hull, U.K
| | - Andrew F James
- Cardiovascular Research Laboratories, School of Physiology & Pharmacology, School of Medical Sciences, University of Bristol, Bristol, U.K
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Scridon A, Fouilloux-Meugnier E, Loizon E, Rome S, Julien C, Barrès C, Chevalier P. Long-standing arterial hypertension is associated with Pitx2 down-regulation in a rat model of spontaneous atrial tachyarrhythmias. Europace 2015; 17:160-5. [PMID: 24908044 DOI: 10.1093/europace/euu139] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
AIMS The timecourse of left atrial Pitx2 down-regulation in the setting of atrial tachyarrhythmias remains unknown. Accordingly, we aimed to assess the age dependency of left atrial Pitx2 expression in an experimental model of spontaneous atrial tachyarrhythmias in rats. METHODS AND RESULTS Atrial sampling was performed in three groups (n = 4 each) of young (14-week-old), adult (24-week-old), and ageing (48-week-old) spontaneously hypertensive rats (SHRs), in which we previously demonstrated the age dependency of spontaneous atrial tachyarrhythmias, and three groups (n = 4 each) of age-matched normotensive Wistar-Kyoto (WKY) rats. mRNA expression of Pitx2 was studied using real-time polymerase chain reaction. Ageing SHRs presented significantly lower left atrial Pitx2 expressions compared with age-matched WKY rats (P = 0.02), while no significant difference was observed between young or adult SHRs and age-matched WKY rats (both P > 0.05). Among SHRs, Pitx2 expressions showed a progressive, age-dependent decrease (34.9 ± 6.7 in young SHRs, 17.1 ± 3.6 in adult SHRs, and 10.7 ± 1.7 in ageing SHRs, P = 0.04) and were significantly negatively correlated with both age (Spearman r = -0.86, P < 0.01) and heart weight (Spearman r = -0.76, P < 0.01). CONCLUSION The present study suggests the presence of age-dependent left atrial Pitx2 down-regulation in SHRs. The strong negative correlation between left atrial Pitx2 expression and heart weight among SHRs may indicate a link between long-standing arterial hypertension and Pitx2-related atrial arrhythmogenicity.
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Affiliation(s)
- Alina Scridon
- Physiology Department, University of Medicine and Pharmacy of Tîrgu Mureş, Tîrgu Mureş 540139, Romania Unité de Neurocardiologie, EA 4612, Université Lyon 1, Lyon F-69008, France
| | | | | | - Sophie Rome
- Unité 1060 INSERM CarMen, Université Lyon 1, Lyon F-69008, France
| | - Claude Julien
- Unité de Neurocardiologie, EA 4612, Université Lyon 1, Lyon F-69008, France
| | - Christian Barrès
- Unité de Neurocardiologie, EA 4612, Université Lyon 1, Lyon F-69008, France
| | - Philippe Chevalier
- Unité de Neurocardiologie, EA 4612, Université Lyon 1, Lyon F-69008, France Service de Rythmologie, Hospices Civils de Lyon, Hôpital Louis Pradel, 28 Avenue du Doyen Lépine, Bron Cedex 69500, France
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48
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Duration of electrically induced atrial fibrillation is augmented by high voltage of stimulus with higher blood pressure in hypertensive rats. Int J Hypertens 2014; 2014:980505. [PMID: 25328683 PMCID: PMC4195393 DOI: 10.1155/2014/980505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 09/15/2014] [Indexed: 11/29/2022] Open
Abstract
Objective. Many previous clinical studies have suggested that atrial fibrillation (AF) is closely associated with hypertension. However, the benefits of antihypertensive therapy on AF are still inconsistent, and it is necessary to explore the factors augmenting AF in hypertensive rats. The aim of the present study was to investigate the correlation between arterial pressure or voltage stimulus and to the duration of electrically induced AF in normotensive or hypertensive rats. Methods. AF was reproducibly induced by transesophageal atrial burst pacing in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). We did the burst pacing at high (20 V) or low (5 V) voltage. Results. Duration of AF did not correlate with systolic blood pressure (SBP) and stimulus voltage in WKY. However, only in SHR, duration of AF with high stimulus voltage significantly correlated with SBP and was significantly longer in high than in low voltage stimulus. Discussion and Conclusion. Duration of AF is augmented by high voltage stimulus with higher blood pressure in SHR.
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Hohl M, Linz B, Böhm M, Linz D. Obstructive sleep apnea and atrial arrhythmogenesis. Curr Cardiol Rev 2014; 10:362-8. [PMID: 25004989 PMCID: PMC4101201 DOI: 10.2174/1573403x1004140707125137] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 05/22/2014] [Accepted: 05/23/2014] [Indexed: 11/22/2022] Open
Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with relevant morbidity and mortality. Besides hypertension, valvular disease and cardiomyopathy, mainly ischemic and dilated, also other conditions like obesity, alcohol abusus, genetic factors and obstructive sleep apnea (OSA) are discussed to contribute to the progression from paroxysmal to persistent AF. The prevalence of OSA among patients with AF is 40-50%. OSA is characterized by periodic or complete cessation of effective breathing during sleep due to obstruction of the upper airways. Obstructive respiratory events result in acute intrathoracic pressure swings and profound changes in blood gases together leading to atrial stretch and acute sympatho-vagal dysbalance resulting in acute apnea related to electrophysiological and hemodynamic alterations. Additionally, repetitive obstructive events in patients with OSA may lead to sympathetic and neurohumoral activation and subsequent structural and functional changes in the atrium creating an arrhythmogenic substrate for AF in the long run. This review focuses on the acute and chronic effects of negative thoracic pressure swings, changes in blood pressure and sympatho-vagal dysbalance induced by obstructive respiratory events on atrial electrophysiology and atrial structure in patients with obstructive sleep apnea.
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Affiliation(s)
| | | | | | - Dominik Linz
- Klinik fur Innere Medizin III, Kardiologie, Angiologie und Internistische Intensivmedizin, Universitatsklinikum des Saarlandes, Kirrberger Str. 1, Geb. 40, D-66421 Homburg/ Saar, Germany.
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50
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Francia P, Ricotta A, Balla C, Adduci C, Semprini L, Frattari A, Modestino A, Mercanti F, Sensini I, Caprinozzi M, Tocci G, Volpe M. P-wave duration in lead aVR and the risk of atrial fibrillation in hypertension. Ann Noninvasive Electrocardiol 2014; 20:167-74. [PMID: 25200638 DOI: 10.1111/anec.12197] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Hypertension entails atrial remodeling that affect P-wave (PW) duration on electrocardiogram (ECG). PW indices (e.g., variance, dispersion, and terminal force) are associated with a higher risk for atrial fibrillation (AF), but their calculation requires multiple measurements of PW duration, limiting their use in clinical practice. We evaluated whether PW duration in specific ECG leads may identify patients with increased susceptibility to AF in a population of hypertensive patients. METHODS In a case-control study, AF and control subjects were matched for age, sex, and left atrial (LA) dimensions. PW duration was measured from digitally stored ECGs. Logistic regression was used to assess the association of PW duration and indices with AF. RESULTS We enrolled 44 hypertensive AF patients (16 paroxysmal and 28 persistent) and 44 hypertensive controls. AF and control subjects were matched for sex (males, n = 27), age (67 ± 8 years), LA diameter (40 ± 5 mm), and were comparable for left ventricular mass (45 ± 11 g/m(2.7) vs 48 ± 12 g/m(2.7) , P = 0.19), ejection fraction (58 ± 7% in both groups), and prevalence of mild valvular heart disease (7% vs 5%; P = 0.64). PW duration in lead aVR was significantly higher in AF patients as compared with controls (115 ± 18 ms vs 101 ± 14 ms; P < 0.0001) and was the best independent predictor of AF in multivariable logistic regression (PW ≥ 100 ms: RR = 3.7; 95% CI: 1.3-10.3; P = 0.02). CONCLUSIONS Simple measurement of PW duration in lead aVR allows effective identification of AF patients in a population of hypertensives. Confirmation of this finding in a larger population would provide a simple and effective risk marker of AF in hypertensive patients.
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Affiliation(s)
- Pietro Francia
- Division of Cardiology, Department of Clinical and Molecular Medicine, St. Andrea Hospital, Sapienza University, Rome, Italy
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