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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 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 -
Progress in Biophysics and Molecular... Jan 2016Many cardiac electrophysiological abnormalities are accompanied by autonomic nervous system dysfunction. Here, we review mechanisms by which the cardiac nervous system... (Review)
Review
Many cardiac electrophysiological abnormalities are accompanied by autonomic nervous system dysfunction. Here, we review mechanisms by which the cardiac nervous system controls normal and abnormal excitability and may contribute to atrial and ventricular tachyarrhythmias. Moreover, we explore the potential antiarrhythmic and/or arrhythmogenic effects of modulating the autonomic nervous system by several strategies, including ganglionated plexi ablation, vagal and spinal cord stimulations, and renal sympathetic denervation as therapies for atrial and ventricular arrhythmias.
Topics: Animals; Heart Atria; Heart Diseases; Heart Ventricles; Humans; Nervous System Physiological Phenomena
PubMed: 26780507
DOI: 10.1016/j.pbiomolbio.2015.12.015 -
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 -
Open Heart Feb 2022
Topics: Atrial Fibrillation; Endurance Training; Exercise; Heart Atria; Humans; Organ Size; Risk Assessment; Risk Factors; Sedentary Behavior
PubMed: 35165169
DOI: 10.1136/openhrt-2022-001962 -
Circulation Journal : Official Journal... 2016Catheter ablation of atrial fibrillation (AF) has evolved over the past 20 years from being a novel, unproven procedure to a commonly performed procedure. Triggers are... (Review)
Review
Catheter ablation of atrial fibrillation (AF) has evolved over the past 20 years from being a novel, unproven procedure to a commonly performed procedure. Triggers are important for the initiation of AF and a suitable substrate is important for perpetuation of AF. Remodeling, including electrical and structural remodeling, is common in patients with persistent AF. Therefore, targeting the remodeled atrium is a critical issue during persistent AF ablation. However, ablation outcomes remain suboptimal despite aggressive substrate modification. Empirical linear ablation is not recommended because of the difficulty in achieving complete linear block and it is recommended only if macroreentry tachycardia develops during the procedure. Complex fractionated atrial electrogram (CFAE) ablation is recommended in the Heart Rhythm Society Consensus Document but efficacy has been limited in long-term follow-up studies. Rotor ablation is controversial. A combined approach using CFAE, similarity and phase mappings with rotor identification may be helpful in searching for AF sources and subsequent substrate ablation. Nevertheless, more prospective randomized studies are required to validate efficacy and safety.
Topics: Atrial Fibrillation; Catheter Ablation; Heart Atria; Humans; Tachycardia
PubMed: 26763467
DOI: 10.1253/circj.CJ-15-1366 -
Circulation. Cardiovascular Imaging Jun 2023Left atrial (LA) function following catheter or surgical ablation of de-novo long-standing persistent atrial fibrillation (AF) and its impact on AF recurrence was... (Clinical Trial)
Clinical Trial
BACKGROUND
Left atrial (LA) function following catheter or surgical ablation of de-novo long-standing persistent atrial fibrillation (AF) and its impact on AF recurrence was studied in patients participating in the CASA-AF trial (Catheter Ablation vs. Thoracoscopic Surgical Ablation in Long Standing Persistent Atrial Fibrillation).
METHODS
All patients underwent echocardiography preablation, 3 and 12 months post-ablation. LA structure and function were assessed by 2-dimensional volume and speckle tracking strain measurements of LA reservoir, conduit, and contractile strain. Left ventricular diastolic function was measured using transmitral Doppler filling velocities and myocardial tissue Doppler velocities to derive the e', E/e', and E/A ratios. Continuous rhythm monitoring was achieved using an implantable loop recorder.
RESULTS
Eighty-three patients had echocardiographic data suitable for analysis. Their mean age was 63.6±9.7 years, 73.5% were male, had AF for 22.8±11.6 months, and had a mean LA maximum volume of 48.8±13.8 mL/m. Thirty patients maintained sinus rhythm, and 53 developed AF recurrence. Ablation led to similar reductions in LA volumes at follow-up in both rhythm groups. However, higher LA emptying fraction (36.3±10.6% versus 27.9±9.9%; <0.001), reservoir strain (22.6±8.5% versus 16.7±5.7%; =0.001), and contractile strain (9.2±3.4% versus 5.6±2.5%; <0.001) were noted in the sinus rhythm compared with AF recurrence group following ablation at 3 months. Diastolic function was better in the sinus rhythm compared with the AF recurrence group with an E/A ratio of 1.5±0.5 versus 2.2±1.2 (<0.001) and left ventricular E/e' ratio of 8.0±2.1 versus 10.3±4.1 (<0.001), respectively. LA contractile strain at 3 months was the only independent predictor of AF recurrence.
CONCLUSIONS
Following ablation for long-standing persistent AF, improvement in LA function was greater in those who maintained sinus rhythm. LA contractile strain at 3 months was the most important determinant of AF recurrence following ablation.
REGISTRATION
URL: https://www.
CLINICALTRIALS
gov; Unique identifier: NCT02755688.
Topics: Aged; Female; Humans; Male; Middle Aged; Atrial Fibrillation; Atrial Function, Left; Catheter Ablation; Echocardiography; Heart Atria; Recurrence; Treatment Outcome
PubMed: 37288553
DOI: 10.1161/CIRCIMAGING.123.015352 -
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 -
Circulation Research Apr 2014Atrial fibrillation (AF) is a complex disease with multiple inter-relating causes culminating in rapid, seemingly disorganized atrial activation. Therapy targeting AF is... (Review)
Review
Atrial fibrillation (AF) is a complex disease with multiple inter-relating causes culminating in rapid, seemingly disorganized atrial activation. Therapy targeting AF is rapidly changing and improving. The purpose of this review is to summarize current state-of-the-art diagnostic and therapeutic modalities for treatment of AF. The review focuses on reviewing treatment as it relates to the pathophysiological basis of disease and reviews preclinical and clinical evidence for potential new diagnostic and therapeutic modalities, including imaging, biomarkers, pharmacological therapy, and ablative strategies for AF. Current ablation and drug therapy approaches to treating AF are largely based on treating the arrhythmia once the substrate occurs and is more effective in paroxysmal AF rather than persistent or permanent AF. However, there is much research aimed at prevention strategies, targeting AF substrate, so-called upstream therapy. Improved diagnostics, using imaging, genetics, and biomarkers, are needed to better identify subtypes of AF based on underlying substrate/mechanism to allow more directed therapeutic approaches. In addition, novel antiarrhythmics with more atrial specific effects may reduce limiting proarrhythmic side effects. Advances in ablation therapy are aimed at improving technology to reduce procedure time and in mechanism-targeted approaches.
Topics: Action Potentials; Animals; Anti-Arrhythmia Agents; Atrial Fibrillation; Catheter Ablation; Diffusion of Innovation; Forecasting; Heart Atria; Heart Conduction System; Humans; Treatment Outcome
PubMed: 24763469
DOI: 10.1161/CIRCRESAHA.114.302362 -
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