Atrial Fibrillation

BACKGROUND: It remains unclear whether atrial fibrillation (AF) is maintained by the rotor. OBJECTIVE: We evaluated the role of the rotor and examined its mechanism. METHODS: Among 75 patients with AF (60 paroxysmal, 15 persistent AF) who underwent 3-dimensional noncontact left atrial mapping during AF, we examined the prevalence and location of rotor activation and elucidated its mechanism. Catheter ablation was performed in a stepwise fashion (linear roof lesion and complex fractionated atrial electrogram ablation after pulmonary vein [PV) isolation) until AF termination...

Atrial fibrillation (AF) is the most common arrhythmia encountered by cardiologists and is a major cause of morbidity and mortality. Risk factors for AF include age, male sex, genetic predisposition, hypertension, diabetes mellitus, sleep apnea, obesity, excessive alcohol, smoking, hyperthyroidism, pulmonary disease, air pollution, heart failure, and possibly excessive exercise. The management of AF involves decisions about rate versus rhythm control. Asymptomatic patients are generally managed with rate control and anticoagulation...

BACKGROUND: Adenosine provokes atrial fibrillation (AF) with a higher activation frequency in right atria (RA) versus left atria (LA) in patients, but the underlying molecular and functional substrates are unclear. We tested the hypothesis that adenosine-induced AF is driven by localized reentry in RA areas with highest expression of adenosine A1 receptor and its downstream GIRK (G protein-coupled inwardly rectifying potassium channels) channels (IK,Ado). METHODS: We applied biatrial optical mapping and immunoblot mapping of various atrial regions to reveal the mechanism of adenosine-induced AF in explanted failing and nonfailing human hearts (n=37)...

Atrial fibrillation (AF) and heart failure (HF) are evolving epidemics, together responsible for substantial human suffering and health-care expenditure. Ageing, improved cardiovascular survival, and epidemiological transition form the basis for their increasing global prevalence. Although we now have a clear picture of how HF promotes AF, gaps remain in our knowledge of how AF exacerbates or even causes HF, and how the development of HF affects the outcome of patients with AF. New data regarding HF with preserved ejection fraction and its unique relationship with AF suggest a possible role for AF in its aetiology, possibly as a trigger for ventricular fibrosis...

Atrial fibrillation (AF) is prevalent in cardiac channelopathies and may be the presenting feature in some patients. The pathogenesis is related to the primary ion channel dysfunction in atrial myocytes that affects atrial conduction or repolarization. The development of AF is associated with adverse outcomes, and its management is challenging in these patients. In this article we review the current information on the prevalence, risk factors, pathophysiology, and treatment of AF in specific cardiac channelopathies...

Catheter ablation is increasingly offered to patients who suffer from symptoms due to atrial fibrillation (AF), based on a growing body of evidence illustrating its efficacy compared with antiarrhythmic drug therapy. Approximately one-third of AF ablation procedures are currently performed in patients with persistent or long-standing persistent AF. Here, we review the available information to guide catheter ablation in these more chronic forms of AF. We identify the following principles: Our clinical ability to discriminate paroxysmal and persistent AF is limited...

AIMS: The primary safety and efficacy endpoints of the randomized FIRE AND ICE trial have recently demonstrated non-inferiority of cryoballoon vs. radiofrequency current (RFC) catheter ablation in patients with drug-refractory symptomatic paroxysmal atrial fibrillation (AF). The aim of the current study was to assess outcome parameters that are important for the daily clinical management of patients using key secondary analyses. Specifically, reinterventions, rehospitalizations, and quality-of-life were examined in this randomized trial of cryoballoon vs...

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OBJECTIVE: We present the first testing study on the ABLA-BOX, a new in vitro module of hybrid atrial fibrillation ablation. METHODS: ABLA-BOX consists of two chambers that mimic the epicardial and endocardial sides of the heart. The septum between chambers provides catheter access on both sites of the cardiac tissue. A circuit, filled with freshly obtained porcine blood, including a pump, an oxygenator, and a heating device, circulate the blood inside the system...

BACKGROUND: In experimental models, stellate ganglion block (SGB) reduces the induction of atrial fibrillation (AF), while data in humans are limited. OBJECTIVE: The aim of this study was to assess the effect of unilateral SGB on atrial electrophysiological properties and AF induction in patients with paroxysmal AF. METHODS: Thirty-six patients with paroxysmal AF were randomized in a 2:1 order to temporary, transcutaneous, pharmaceutical SGB with lidocaine or placebo before pulmonary vein isolation...

AIMS: Physical activity is protective against cardiovascular (CV) events, both in general population and in high-risk CV cohorts. However, the relationship between physical activity with major adverse outcomes in atrial fibrillation (AF) is not well-established. Our aim was to analyse this relationship in a 'real-world' AF population. Second, we investigated the influence of physical activity on arrhythmia progression. METHODS AND RESULTS: We studied all patients enrolled in the EURObservational Research Programme on AF (EORP-AF) Pilot Survey...

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and affects over 33 million people worldwide. AF is associated with stroke and systemic thromboembolism, unpleasant symptoms and reduced quality of life, heart failure, and increased mortality, and treatment of AF and its complications are associated with significant cost. Antiarrhythmic drugs (AADs) can suppress AF, allowing long-term maintenance of sinus rhythm, and have the potential to relieve symptoms and reverse or prevent adverse effects associated with AF...

Aims: Although atrial fibrillation (AF) catheter ablation increases sinus heart rate (HR), its mechanism and prognosis have not yet been clearly elucidated. We hypothesize that post-AF ablation high sinus HR (PA-HSR) is associated with a better clinical outcome of AF ablation without adverse cardiac effects. Methods and results: We studied 991 AF patients (75% male, 58 ± 11 years old, 70% paroxysmal AF) with HR variability (HRV) at 3 months and 1 year after catheter ablation, and pre- and post-1-year echocardiograms...

AIMS: The objective was to examine the association of physical activity and resting heart rate (RHR) with hospital-diagnosed atrial fibrillation (AF) in a Norwegian cohort. METHODS AND RESULTS: This prospective study included 20 484 adults (50.3% men) who participated in the third Tromsø Study survey in 1986-87. At baseline, physical activity was assessed by a validated questionnaire, and RHR was objectively measured. Participants were followed from baseline through 2010 with respect to incident cases of hospital-diagnosed AF documented on an electrocardiogram...

BACKGROUND: Vanoxerine is an oral, 1,4-dialkylpiperazine derivative antiarrhythmic drug being evaluated for pharmacological cardioversion of atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to evaluate the safety and efficacy of vanoxerine for the restoration of sinus rhythm in subjects with recent onset AF or atrial flutter (AFL). METHODS: RESTORE SR (randomized, double-blind, placebo-controlled study to evaluate the safety and efficacy of a single oral dose of vanoxerine for the conversion of subjects with recent onset atrial fibrillation or flutter to normal sinus rhythm) was a prospective, multinational, randomized, double-blind, placebo-controlled trial that randomized subjects to a single oral dose of vanoxerine 400 mg or placebo (2:1 allocation)...

BACKGROUND: The cardiac late sodium current (INa) has been increasingly implicated in the initiation of atrial fibrillation (AF). Eleclazine (formerly known as GS-6615) is a new selective late INa inhibitor and is undergoing clinical testing for the treatment of cardiac arrhythmias. OBJECTIVE: We tested whether late INa inhibition by eleclazine confers protection against atrial premature beats (APBs) and AF. METHODS: In closed-chest anesthetized Yorkshire pigs, epinephrine (2...

BACKGROUND: Insertable cardiac monitors (ICMs) are used for long-term ECG monitoring. The Reveal LINQ ICM has an improved atrial fibrillation (AF) detection algorithm. OBJECTIVE: The purpose of this study was to investigate the algorithm's real-world performance in patients with syncope, cryptogenic stroke, and known AF. METHODS: Consecutive patients with implanted ICM and AF detection parameters automatically set and maintained depending on the indication for monitoring were included...

Although considerable progress has been made in developing ablation approaches to cure atrial fibrillation (AF), outcomes are still suboptimal, especially for persistent and long-lasting persistent AF. In this topical review, we review the arrhythmia mechanisms, both reentrant and nonreentrant, that are potentially relevant to human AF at various stages/settings. We describe arrhythmia mapping techniques used to distinguish between the different mechanisms, with a particular focus on the detection of rotors...

AIM: It is unclear if catheter ablation for atrial fibrillation (AF) affects the prognosis or merely is a symptomatic treatment. The aim is to study the association between ablation for AF, ischaemic stroke, and mortality. METHODS AND RESULTS: We identified all 361 913 patients with a diagnosis of AF in the Swedish Patient Register. During a 7-year period, 5176 AF ablations were performed among 4278 individuals. Patients who had undergone catheter ablation were younger (58...

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