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Circulation Research Apr 2014Autonomic nervous system activation can induce significant and heterogeneous changes of atrial electrophysiology and induce atrial tachyarrhythmias, including atrial... (Review)
Review
Autonomic nervous system activation can induce significant and heterogeneous changes of atrial electrophysiology and induce atrial tachyarrhythmias, including atrial tachycardia and atrial fibrillation (AF). The importance of the autonomic nervous system in atrial arrhythmogenesis is also supported by circadian variation in the incidence of symptomatic AF in humans. Methods that reduce autonomic innervation or outflow have been shown to reduce the incidence of spontaneous or induced atrial arrhythmias, suggesting that neuromodulation may be helpful in controlling AF. In this review, we focus on the relationship between the autonomic nervous system and the pathophysiology of AF and the potential benefit and limitations of neuromodulation in the management of this arrhythmia. We conclude that autonomic nerve activity plays an important role in the initiation and maintenance of AF, and modulating autonomic nerve function may contribute to AF control. Potential therapeutic applications include ganglionated plexus ablation, renal sympathetic denervation, cervical vagal nerve stimulation, baroreflex stimulation, cutaneous stimulation, novel drug approaches, and biological therapies. Although the role of the autonomic nervous system has long been recognized, new science and new technologies promise exciting prospects for the future.
Topics: Action Potentials; Animals; Anti-Arrhythmia Agents; Atrial Fibrillation; Atrial Function; Autonomic Denervation; Autonomic Nervous System; Catheter Ablation; Heart Atria; Humans; Risk Factors; Treatment Outcome
PubMed: 24763467
DOI: 10.1161/CIRCRESAHA.114.303772 -
Journal of the American College of... Dec 2014
Review
2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society.
Topics: Anti-Arrhythmia Agents; Anticoagulants; Arrhythmias, Cardiac; Atrial Fibrillation; Autonomic Nervous System; C-Reactive Protein; Cardiac Output, Low; Catheter Ablation; Comorbidity; Defibrillators, Implantable; Echocardiography, Transesophageal; Electric Countershock; Electrocardiography; Fibrinolytic Agents; Heart Atria; Heart Conduction System; Humans; Inflammation; Natriuretic Peptide, Brain; Oxidative Stress; Pacemaker, Artificial; Platelet Aggregation Inhibitors; Renin-Angiotensin System; Risk Assessment; Risk Factors; Septal Occluder Device; Stroke; Thromboembolism; Ventricular Remodeling
PubMed: 24685669
DOI: 10.1016/j.jacc.2014.03.022 -
Cardiovascular Diabetology Jan 2021Sodium-glucose linked transporter type 2 (SGLT-2) inhibition has been shown to reduce cardiovascular mortality in heart failure independently of glycemic control and...
BACKGROUND
Sodium-glucose linked transporter type 2 (SGLT-2) inhibition has been shown to reduce cardiovascular mortality in heart failure independently of glycemic control and prevents the onset of atrial arrhythmias, a common co-morbidity in heart failure with preserved ejection fraction (HFpEF). The mechanism behind these effects is not fully understood, and it remains unclear if they could be further enhanced by additional SGLT-1 inhibition. We investigated the effects of chronic treatment with the dual SGLT-1&2 inhibitor sotagliflozin on left atrial (LA) remodeling and cellular arrhythmogenesis (i.e. atrial cardiomyopathy) in a metabolic syndrome-related rat model of HFpEF.
METHODS
17 week-old ZSF-1 obese rats, a metabolic syndrome-related model of HFpEF, and wild type rats (Wistar Kyoto), were fed 30 mg/kg/d sotagliflozin for 6 weeks. At 23 weeks, LA were imaged in-vivo by echocardiography. In-vitro, Ca transients (CaT; electrically stimulated, caffeine-induced) and spontaneous Ca release were recorded by ratiometric microscopy using Ca-sensitive fluorescent dyes (Fura-2) during various experimental protocols. Mitochondrial structure (dye: Mitotracker), Ca buffer capacity (dye: Rhod-2), mitochondrial depolarization (dye: TMRE) and production of reactive oxygen species (dye: H2DCF) were visualized by confocal microscopy. Statistical analysis was performed with 2-way analysis of variance followed by post-hoc Bonferroni and student's t-test, as applicable.
RESULTS
Sotagliflozin ameliorated LA enlargement in HFpEF in-vivo. In-vitro, LA cardiomyocytes in HFpEF showed an increased incidence and amplitude of arrhythmic spontaneous Ca release events (SCaEs). Sotagliflozin significantly reduced the magnitude of SCaEs, while their frequency was unaffected. Sotagliflozin lowered diastolic [Ca] of CaT at baseline and in response to glucose influx, possibly related to a ~ 50% increase of sodium sodium-calcium exchanger (NCX) forward-mode activity. Sotagliflozin prevented mitochondrial swelling and enhanced mitochondrial Ca buffer capacity in HFpEF. Sotagliflozin improved mitochondrial fission and reactive oxygen species (ROS) production during glucose starvation and averted Ca accumulation upon glycolytic inhibition.
CONCLUSION
The SGLT-1&2 inhibitor sotagliflozin ameliorated LA remodeling in metabolic HFpEF. It also improved distinct features of Ca-mediated cellular arrhythmogenesis in-vitro (i.e. magnitude of SCaEs, mitochondrial Ca buffer capacity, diastolic Ca accumulation, NCX activity). The safety and efficacy of combined SGLT-1&2 inhibition for the treatment and/or prevention of atrial cardiomyopathy associated arrhythmias should be further evaluated in clinical trials.
Topics: Animals; Arrhythmias, Cardiac; Atrial Function, Left; Atrial Remodeling; Calcium Signaling; Disease Models, Animal; Glycosides; Heart Atria; Heart Failure; Metabolic Syndrome; Mitochondria, Heart; Mitochondrial Dynamics; Mitochondrial Swelling; Rats, Inbred WKY; Rats, Zucker; Reactive Oxygen Species; Sodium-Calcium Exchanger; Sodium-Glucose Transporter 1; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Rats
PubMed: 33413413
DOI: 10.1186/s12933-020-01208-z -
Journal of Cardiovascular... Oct 2021Atrial fibrillation (AF) is the most common arrhythmia among adults. While there have been incredible advances in the management of AF and its clinical sequelae,... (Review)
Review
Atrial fibrillation (AF) is the most common arrhythmia among adults. While there have been incredible advances in the management of AF and its clinical sequelae, investigation of atrial cardiomyopathies (ACMs) is becoming increasingly more prominent. ACM refers to the electromechanical changes-appreciated subclinically and/or clinically-that underlie atrial dysfunction and create an environment ripe for the development of clinically apparent AF. There are several subtypes of ACM, distinguished by histologic features. Recent progress in cardiovascular imaging, including echocardiography with speckle-tracking (e.g., strain analysis), cardiovascular magnetic resonance imaging (CMR), and atrial 4-D flow CMR, has enabled increased recognition of ACM. Identification of ACM and its features carry clinical implications, including elevating a patient's risk for development of AF, as well as associations with outcomes related to catheter-based and surgical AF ablation. In this review, we explore the definition and classifications of ACM, its complex relationship with clinical AF, imaging modalities, and clinical implications. We propose next steps for a more unified approach to ACM recognition that can direct further research into this complex field.
Topics: Adult; Atrial Fibrillation; Cardiomyopathies; Catheter Ablation; Echocardiography; Heart Atria; Humans
PubMed: 33993617
DOI: 10.1111/jce.15083 -
Medical & Biological Engineering &... Apr 2023The inverse problem of electrocardiography or electrocardiographic imaging (ECGI) is a technique for reconstructing electrical information about cardiac surfaces from... (Review)
Review
The inverse problem of electrocardiography or electrocardiographic imaging (ECGI) is a technique for reconstructing electrical information about cardiac surfaces from noninvasive or non-contact recordings. ECGI has been used to characterize atrial and ventricular arrhythmias. Although it is a technology with years of progress, its development to characterize atrial arrhythmias is challenging. Complications can arise when trying to describe the atrial mechanisms that lead to abnormal propagation patterns, premature or tachycardic beats, and reentrant arrhythmias. This review addresses the various ECGI methodologies, regularization methods, and post-processing techniques used in the atria, as well as the context in which they are used. The current advantages and limitations of ECGI in the fields of research and clinical diagnosis of atrial arrhythmias are outlined. In addition, areas where ECGI efforts should be concentrated to address the associated unsatisfied needs from the atrial perspective are discussed.
Topics: Humans; Atrial Fibrillation; Body Surface Potential Mapping; Electrocardiography; Heart Atria; Diagnostic Imaging
PubMed: 36370321
DOI: 10.1007/s11517-022-02709-7 -
Advances in Clinical and Experimental... 2017Bradycardia, atrial stretch and dilatation, autonomic nervous system disorders, and the presence of triggers such as atrial premature contractions, are factors which... (Review)
Review
Bradycardia, atrial stretch and dilatation, autonomic nervous system disorders, and the presence of triggers such as atrial premature contractions, are factors which predispose a person to paroxysmal AF. Atrial pacing not only eliminates bradycardia but also prevents atrial premature contractions and dispersion of refractoriness, which are a substrate for atrial fibrillation. As the prolonged duration of atrial activation during pacing, especially from locations changing the physiological pattern of this activation (right atrium lateral wall, right atrium appendage), negatively influences both a mechanical and an electrical function of the atria, the atrial pacing site affects an atrial arrhythmogenesis. A conventional atrial lead location in the right atrium appendage causes non-physiological activation propagation, resulting in a prolongation of the activation time of both atria. This location is optimal according to a passive fixation of the atrial lead but the available contemporary active fixation leads could potentially be located in any area of the atrium. There is growing evidence of the benefit of pacing, imitating the physiological propagation of impulses within the atria. It seems that the Bachmann's bundle pacing is the best pacing site within the atria, not only positively influencing the atrial mechanical function but also best fulfilling the so-called atrial resynchronization function, in particular in patients with interatrial conduction delay. It can be effectively achieved using only one atrial electrode, and the slight shortening of atrioventricular conduction provides an additional benefit of this atrial pacing site.
Topics: Arrhythmias, Cardiac; Atrial Fibrillation; Cardiac Pacing, Artificial; Heart Atria; Heart Conduction System; Humans; Reproducibility of Results; Treatment Outcome
PubMed: 28791857
DOI: 10.17219/acem/61429 -
Cardiology Clinics Nov 2014Atrial fibrillation is the most common cardiac arrhythmia, and its treatment options include drug therapy or catheter-based or surgical interventions. The surgical... (Review)
Review
Atrial fibrillation is the most common cardiac arrhythmia, and its treatment options include drug therapy or catheter-based or surgical interventions. The surgical treatment of atrial fibrillation has undergone multiple evolutions over the last several decades. The Cox-Maze procedure went on to become the gold standard for the surgical treatment of atrial fibrillation and is currently in its fourth iteration (Cox-Maze IV). This article reviews the indications and preoperative planning for performing a Cox-Maze IV procedure. This article also reviews the literature describing the surgical results for both approaches including comparisons of the Cox-Maze IV to the previous cut-and-sew method.
Topics: Atrial Fibrillation; Catheter Ablation; Heart Atria; Heart Conduction System; Humans; Intraoperative Care; Minimally Invasive Surgical Procedures; Outcome Assessment, Health Care; Recurrence
PubMed: 25443237
DOI: 10.1016/j.ccl.2014.07.003 -
International Journal of Molecular... Mar 2021Atrial fibrillation (AF) is one of the most common tachyarrhythmias observed in the clinic and is characterized by structural and electrical remodelling. Atrial...
Atrial fibrillation (AF) is one of the most common tachyarrhythmias observed in the clinic and is characterized by structural and electrical remodelling. Atrial fibrosis, an emblem of atrial structural remodelling, is a complex multifactorial and patient‑specific process involved in the occurrence and maintenance of AF. Whilst there is already considerable knowledge regarding the association between AF and fibrosis, this process is extremely complex, involving intricate neurohumoral and cellular and molecular interactions, and it is not limited to the atrium. Current technological advances have made the non‑invasive evaluation of fibrosis in the atria and ventricles possible, facilitating the selection of patient‑specific ablation strategies and upstream treatment regimens. An improved understanding of the mechanisms and roles of fibrosis in the context of AF is of great clinical significance for the development of treatment strategies targeting the fibrous region. In the present review, a focus was placed on the atrial fibrosis underlying AF, outlining its role in the occurrence and perpetuation of AF, by reviewing recent evaluations and potential treatment strategies targeting areas of fibrosis, with the aim of providing a novel perspective on the management and prevention of AF.
Topics: Atrial Fibrillation; Atrial Remodeling; Fibrosis; Heart Atria; Heart Ventricles; Humans
PubMed: 33448312
DOI: 10.3892/ijmm.2020.4842 -
Biochimica Et Biophysica Acta Jul 2016Atrial cardiomyocytes are essential for fluid homeostasis, ventricular filling, and survival, yet their cell biology and physiology are incompletely understood. It has... (Review)
Review
Atrial cardiomyocytes are essential for fluid homeostasis, ventricular filling, and survival, yet their cell biology and physiology are incompletely understood. It has become clear that the cell fate of atrial cardiomyocytes depends significantly on transcription programs that might control thousands of differentially expressed genes. Atrial muscle membranes propagate action potentials and activate myofilament force generation, producing overall faster contractions than ventricular muscles. While atria-specific excitation and contractility depend critically on intracellular Ca(2+) signalling, voltage-dependent L-type Ca(2+) channels and ryanodine receptor Ca(2+) release channels are each expressed at high levels similar to ventricles. However, intracellular Ca(2+) transients in atrial cardiomyocytes are markedly heterogeneous and fundamentally different from ventricular cardiomyocytes. In addition, differential atria-specific K(+) channel expression and trafficking confer unique electrophysiological and metabolic properties. Because diseased atria have the propensity to perpetuate fast arrhythmias, we discuss our understanding about the cell-specific mechanisms that lead to metabolic and/or mitochondrial dysfunction in atrial fibrillation. Interestingly, recent work identified potential atria-specific mechanisms that lead to early contractile dysfunction and metabolic remodelling, suggesting highly interdependent metabolic, electrical, and contractile pathomechanisms. Hence, the objective of this review is to provide an integrated model of atrial cardiomyocytes, from tissue-specific cell properties, intracellular metabolism, and excitation-contraction (EC) coupling to early pathological changes, in particular metabolic dysfunction and tissue remodelling due to atrial fibrillation and aging. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.
Topics: Action Potentials; Animals; Atrial Fibrillation; Atrial Function; Atrial Remodeling; Calcium Signaling; Cell Differentiation; Cell Lineage; Heart Atria; Humans; Myocardial Contraction; Myocytes, Cardiac; Phenotype
PubMed: 26620800
DOI: 10.1016/j.bbamcr.2015.11.025 -
Physiological Reports Feb 2016
Topics: Arrhythmias, Cardiac; Fibroblasts; Heart Atria; Humans
PubMed: 26869687
DOI: 10.14814/phy2.12711