Abstract Atrial Fibrillation Research Articles

What after cryptogenic stroke – NOAC for everyone or ICM for some?

Atrial fibrillation (AF) is by far the most common cause of stroke with cardiovascular etiology. It is commonly believed that a significant proportion of ischemic strokes of an unknown cause are in fact also embolic (ESUS). This leads to consideration that patients after ESUS are potential candidates for chronic NOAC treatment. However, the therapeutic strategy constructed in such a simple way has been verified negatively in recent randomized trials. It is uncertain whether the pharmaceutical industry will be interested in continuing research in a subpopulation of ESUS patients with a particularly high risk of AF. However, it is now possible to strive for extended ECG monitoring aimed at detecting paroxysmal AF that is not detected by standard post-stroke diagnostic workup. In both scenarios, pragmatic and economic considerations make it necessary to develop a method of proper patients selection. The discussed analysis of data collected during the CRYSTAL-AF study, discussed by me, allows to better understand the imperfection of the current thinking about ESUS and provides information that may development the creation of an optimal model for dealing with this group of patients.

Abstract WP335: Role of Sorbs2 Gene in the Development of Atrial Cardiomyopathy and Atrial Fibrillation in Mice

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is a major cause of thromboembolic stroke in the United States. The risk of stroke is a 5-fold increase in patients with AF. The Sorbin and SH3 domain-containing protein 2 (Sorbs2) is a scaffolding protein known to interact with actin and several other cytoskeletal proteins in the intercalated discs and Z band of cardiomyocytes. However, the role of Sorbs2 gene in cardiovascular diseases is largely unknown. Using the loss-of-function of Sorbs2 ( Sorbs2 e8/e8 ) mice, we found that Sorbs2 e8/e8 mice had an abnormal lifespan and die at 4 to 7 months of age. Echocardiogram examine revealed that there was a significant decrease in right ventricle (RV) and left ventricular (LV) ejection fraction (EF), increase in RV end-diastolic volume (EDV) and end-systolic volume (ESV), and progressive chamber enlargement in left atria (LA) and RV, particularly in LA with severe fibrosis and intramural thrombus formation, in Sorbs2 e8/e8 mice after 3 months of age. Surface electrocardiograph also showed a significant conduction delay and spontaneous arrhythmias including those of bifid P wave configuration, right bundle branch block (RBBB), spontaneous AF and non-sustained ventricular tachycardia (VT) in Sorbs2 e8/e8 mice. Intracellular recordings in the freshly isolated LA demonstrated that Sorbs2 e8/e8 myocardium had a delayed action potential activation in response to electrical impulse excitation, reduced amplitude and upstroke velocity (dV/dt) at phase 0, slowed repolarization at phase 1 and phase 2, prolonged atrial effective refractory period (aERP), action potential durations at 50% (APD 50 ) and 90% (APD 90 ) repolarization, and decreased resting potentials. Moreover, the mRNA and protein expressions of voltage-gated Na + channels, L-type Ca 2+ channels, transient outward K + channels and inward rectifier K + channels were significantly downregulated in the LA of Sorbs2 e8/e8 mice, compared wo those of wild type mice. Our results indicate that Sorbs2 gene plays an important role in atrial myocardium architecture and electrophysiology. Sorbs2 dysfunction leads to atrial cardiomyopathy, spontaneous AF and cardiac embolism in mice. Hence, Sorbs2 is a new genetic association with cardioembolic stroke.

Antidepressants and Atrial Fibrillation: The Importance of Resourceful Statistical Approaches to Address Confounding by Indication.

Atrial fibrillation (AF) is the most common cardiac arrhythmia. Antidepressant drugs are known to influence cardiac conduction, and there are theoretical grounds to suggest that serotonin reuptake inhibition by antidepressants may predispose to AF. A large register-based cohort study found that antidepressant use was associated with an increased risk of AF during the first month following antidepressant initiation. Whereas this may seem alarming, additional analyses found that the risk progressively diminished in succeeding months. Further analysis showed that antidepressant use was associated with an even higher risk of AF in the month before antidepressant initiation; this finding implies that patients who initiate antidepressant drugs are already at increased risk of AF and that the significant association between antidepressant drug use and AF might be because of confounding by indication. In other words, the indication for antidepressant use rather than antidepressant use, itself, may be the risk factor for AF, and this risk is probably state-dependent because it diminishes with the passage of time, during which period the indication for antidepressant use presumably resolves. In another study, which used a nested case-control design, current and recent users of antidepressant drugs were contrasted not with antidepressant nonusers but with past users of antidepressants. The study found that neither current nor recent users were at increased risk of AF. This again indicates that antidepressants are unlikely to directly predispose to AF. In both studies, the possibility of confounding by indication was addressed by resourceful statistical approaches to the research question. Such resourcefulness in analysis is necessary in all observational studies of the association between an exposure and an outcome. In the absence of efforts to address confounding by indication, an identified association between an exposure and an outcome should not be presumed to reflect a cause-effect relationship.

ARENA-Project atrial fibrillation in the Rhein-Neckar region

Atrialfibrillation (AF) isthe most common form of cardiac tachyarrhythmia. It is estimated that in the Rhein-Neckar region approximately 40,000-50,000 out of 2 million people are affected. Due todemographic changes in the near future there will be asignificant increase in the prevalence of AF within the next decades. The ARENA project was initiated by the Foundation Institute for Cardiac Infarction Research (IHF) Ludwigshafen in cooperation with cardiological and neurological departments of neighboring hospitals, resident doctors and pharmacies to improve the awareness and care of patients with AF. The particular aim is theprevention of stroke as one of the most dreaded complications. The project focusses on the following three subtopics: interventions, medication, migration. The aim of the intervention project is to raise awareness of AF as a risk factor for stroke and to improve the diagnostic work-up and care for patients with diagnosed or unknown AF. The subproject medication focusses on the adherence of patients with AF to the prescribed antithrombotic medication. To evaluate differences concerning patients with and without amigration background the subproject migration was initiated.

Treating atrial fibrillation in the 21st Century: part 1

Atrial fibrillation (AF) is the most common pathological cardiac arrhythmia in the horse. While it may be an incidental finding in some horses, it can be an important cause of poor exercise tolerance in the performance horse, especially those working at extremes of cardiac function. Although quinidine sulfate remains the most widely used treatment option for horses, alternatives, such as transvenous electrocardioversion, are growing in popularity. The decision-making process to establish the most appropriate treatment is based on a number of factors including chronicity, underlying disease, and cardiac size. The availability of transvenous electrocardioversion in the horse provides a valid alternative for the treatment of horses with atrial fibrillation.

Atrial fibrillation and concerns in some groups of patients: elderly patients, pregnant women, co-existing hypertrophic cardiomyopathy and WPW syndrome

Atrial fibrillation (AF) is the one of the most frequent arrhythmia in general population. In 2010 all over the world there was 20,9 mln male and 12,6 mln female with this arrhythmia [1-3]. Atrial fibrillation could be totally asymptomatic, thus the number of patients is probably underestimated. AF increases cardiovascular morbidity, and is one of the cause of stroke or heart failure. Due to the fact that AF concerns an increasing number of patients with various comorbidities in some groups of patients, it may pose many clinical problems and require special treatment.

Sleep Disorders and Atrial Fibrillation: Current Situation and Future Directions.

Atrial fibrillation (AF) is a growing health problem worldwide. In recent years, there has been a rising interest in the relationship between sleep disorders and AF. Several studies have reported higher prevalence and incidence rates of AF in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). However, some believe that OSAHS is not a risk factor for AF; but AF, by itself, is regarded as one of the possible triggers for OSAHS. In this study, the related literature investigating the association between OSAHS and AF was reviewed, and then the possible mechanisms of this interplay were discussed. To conclude, recommendations for further research in this field were presented to researchers and some points were highlighted for physicians.

Extended Cardiac Monitoring in Patients with Severe Sleep Apnea and no History of Atrial Fibrillation (The Reveal XT-SA Study)

Atrial fibrillation (AF) is an important risk factor for ischemic stroke and reported to be associated with severe obstructive sleep apnea (OSA). The aim of this study was to determine the occurrence of new onset AF in patients with severe OSA and no prior history of AF. Prospective observational

Radiofrequency catheter ablation prior to percutaneous coronary intervention in patients with atrial fibrillation coexisting with stable coronary artery disease: a single-center pilot study.

Atrial fibrillation (AF) frequently coexists with cardiovascular disease (CAD) in a clinical setting. However, the optimum therapy for AF patients who have concomitant CAD is unclear. We retrospectively examined the efficacy and safety of radiofrequency catheter ablation (RFCA) prior to percutaneous coronary intervention (PCI) in patients with AF who had concomitant stable CAD. Between January 2014 and December 2015, a total 264 patients (179 men; mean age, 65.5 ± 10.1years) who were referred to undergo a first RFCA procedure were reviewed in this study. Of the 264 patients, 41 (15.5%) had stable CAD detected by multi-detector computed tomography before RFCA. Thirty-seven patients who had AF with stable CAD were divided into two treatment arms: (1) RFCA prior to PCI (n = 13) and (2) PCI prior to RFCA (n = 24) [four patients excluded because of left main coronary artery disease (LMCA) or triple vessel disease (TVD)]. The median follow-up was 14 (IQR 8-19) months. There was no significant difference in AF recurrence rate after the procedure between the RFCA first group and PCI first group (P = 0.515). No symptomatic cardiovascular events occurred the during follow-up period. The PCI first group had a significantly longer duration of triple therapy (188.5 ± 167days vs 5.6 ± 24.5days, P = 0.01) and all of the four bleeding events occurred during triple therapy (P = 0.01). The results of this single-center pilot study suggested that prior RFCA in patients with AF coexisting with CAD could have fewer serious bleeding events than prior PCI.

Trends in the Incidence and In-Hospital Outcomes of Patients With Atrial Fibrillation Complicated by Non-ST-Segment Elevation Myocardial Infarction.

Atrial fibrillation (AF) can present with non-ST-segment elevation myocardial infarction (NSTEMI). The incidence, characteristics, outcomes, and treatment of this subgroup of patients with AF remains poorly studied. Using data from the National Inpatient Sample database, we (1) compared baseline characteristics of patients with AF with/without NSTEMI, (2) evaluated their outcomes and associated trends over the study period (2004-2013), and (3) evaluated revascularization (by percutaneous coronary intervention or coronary artery bypass graft [CABG]) and the impact on patient outcomes. Of the 3 923 436 patients admitted with a primary diagnosis of AF, 47 785 (1.2%) had a secondary diagnosis of NSTEMI. In this subgroup with AF and NSTEMI, there was a significant trend toward a decrease in mortality ( P = .002), stroke ( P < .001), and gastrointestinal bleeding ( P < .001) during the study period. Compared to unrevascularized patients, revascularized patients were more likely to be younger (72.2 ± 10.2 vs 77.0 ± 11.8 years old, P < .001), male (57.8 vs 42.7%, P < .001), and had a much higher incidence of coronary risk factors. Revascularization was associated with increased survival in multivariable analysis (odds ratio: 0.562, 95% confidence interval: 0.334-0.946, P = .03). In conclusion, among patients admitted with AF, 1.2% were diagnosed with NSTEMI. A minority of patients with AF and NSTEMI underwent revascularization and had better in-hospital outcomes.

Atrial Fibrillation and Acute Myocardial Infarction – An Inflammation-Mediated Association

ABSTRACT Atrial fibrillation (AF) is an increasingly widespread healthcare problem. AF can frequently present as a complication in acute coronary syndromes (ACS), especially in ST-elevation acute myocardial infarction (AMI), in which case it is the most frequent supraventricular rhythm disturbance with an estimated incidence of 6.8-21%. The presence of AF in ACS heralds worse outcomes in comparison to subjects in sinus rhythm, and several studies have shown that in AMI patients, both new-onset and pre-existing AF are associated with a higher risk of major adverse cardiovascular and cerebrovascular events during hospitalization. The cause of newonset AF in AMI is multifactorial. Although still incompletely understood, the mechanisms involved in the development of AF in acute myocardial ischemic events include the neurohormonal activation of the sympathetic nervous system that accompanies the AMI, ischemic involvement of the atrial myocytes, ventricular dysfunction, and atrial overload. The identification of patients at risk for AF is of great significance as it may lead to prompt therapeutic interventions and closer follow-up, thus improving prognosis and decreasing cardiovascular and cerebrovascular events. The present manuscript aims to summarize the current research findings related to new-onset AF in AMI patients, as well as the predictors and prognostic impact of this comorbid association.

Periprocedural Use of Oral Anticoagulation Therapy in Patients Undergoing Atrial Fibrillation Ablation

Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice today. For those who present with it, one of the most major risks associated with the condition is stroke. AF is associated with a fivefold increased risk of stroke and thromboembolism. Oral anticoagulation has been the cornerstone of stroke prevention in patients with AF. In some individuals who exhibit a higher risk of bleeding, other alternatives for stroke prevention have been sought, including the use of left atrial appendage occlusion devices and surgical exclusion of the left atrial appendage. Catheter ablation is an important treatment strategy in those patients for whom a rhythm control strategy has been selected. This article reviews some of the available anticoagulant drug options and their use prior to, during, and after catheter ablation.

Intrinsic Mode Function Complexity Index Using Empirical Mode Decomposition discriminates Normal Sinus Rhythm and Atrial Fibrillation on a Single Lead ECG.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia affecting approximately 3 million Americans, and is a prognostic marker for stroke, heart failure and even death. Current techniques to discriminate normal sinus rhythm (NSR) and AF from single lead ECG suffer several limitations in terms of sensitivity and specificity using short time ECG data which distorts ECG and many are not suitable for real-time implementation. The purpose of this research was to test the feasibility of discriminating single lead ECG's with normal sinus rhythm (NSR) and AF using intrinsic mode function (IMF) complexity index. 15 sets of ECG's with NSR and AF were obtained from Physionet database. Custom MATLAB® software was written to compute IMF index for each of the data set and compared for statistical significance. The mean IMF index for NSR across 15 data sets was 0.37 ± 0.08, and the mean IMF index for ECG with AF was 0.21 ± 0.07 showing robust discrimination with statistical significance (p<0.01). IMF complexity robustly discriminates single lead ECG with normal sinus rhythm and AF. Further validation of this result is required on a larger dataset. The results also motivate the use of this technique for analysis of other complex cardiac arrhythmias such as ventricular tachycardia (VT) or ventricular fibrillation (VF).

Bispectrum and Histogram Features for the Identification of Atrial Fibrillation Based on Electrocardiogram.

Atrial Fibrillation (AF) is probably the most common serious abnormal heart rhythm. It affects about 2% to 3% of the population in Europe and North America. In this study, we proposed an effective Atrial Fibrillation (AF) identification system based on RR interval (RRI) analysis. Two preprocessing methods were employed to remove the motion artifacts and ectopic beats. Three categories of RRI features, including base, bispectrum, and histogram features, were proposed to enhance the performance of the identifier. The roles of different feature categories were evaluated. The combination of the three categories of features were demonstrated to compensate with one another to construct an effective feature set for AF identification. When compared to other representative AF identifiers in the literature, the proposed method outperforms them with superior recognition rates by using much larger number of testing data.

Evaluation of Multiscale Frequency Approach for Visualizing Rotors in Patients with Atrial Fibrillation.

Atrial Fibrillation (AF) is most common cardiac arrhythmia. It is associated with increased risk of stroke, heart failure and sudden cardiac death. Catheter ablation is a treatment used to control AF and has had suboptimal success for patients with persistent AF, which is primarily maintained by rotors outside of the pulmonary veins (PV) region. The pivot point (core) of the rotor is considered an efficient target for ablation. Currently available electro-anatomical mapping systems cannot accurately predict the exact location of the pivot point of rotors outside of the PV region, so there is a need for novel approaches to accurately identify and distinguish sites for ablation. Recently, a multiscale frequency (MSF) technique was developed for accurate identification of the pivot point of rotors and validated using optical mapping experiments in exvivo rabbit hearts, where electrical activity can be directly visualized. However, the nature of optical signals and its spatial resolution are very different from clinical intracardiac electrograms (iEGM). Here we extend the MSF approach to 3D iEGM and compare its prediction with the traditional dominant frequency (DF) approach, using Pearson's correlation and earth mover's distance methods. Our results demonstrate that the similarity between MSF and DF are high in some regions, but very low in other spatial regions of the human atria. This indicates the inconsistency in the traditional DF approach in identifying pivot points and identifying such low similarity regions can be used to find sites for successful ablation.

The current profile of the patient with atrial fibrillation

Abstract: Atrial fibrillation (AF) is the most common supraventricular arrhythmia, characterized by an irregular and extremely rapid atrial electrical activation that causes loss of atrial mechanical function and important hemodynamic consequences. AF classification is important in both the therapeutic approach and the prognosis. Several classifications based on the ECG patch, epicardial or endocavitary records have been performed over time, but no classification can take into account all the characteristics of AF and especially associated diseases, which may be both the cause and consequence of arrhythmia. Aim: The aim of the study is to establish the current profile of the patient with atrial fibrillation in the new era of oral anticoagulant therapy and sinus rhythm restoration.&#x0D; Material and methods: The trial was conducted on patients with atrial fibrillation hospitalized between 01.10.2014-31.03.2015 at Institute of Cardiovascular Diseases ”Prof. Dr. G. Georgescu”, Iasi. Patients included in the study were analyzed according to age and sex, criteria for the clinical and paraclinic definition for atrial fibrillation.&#x0D; Results: Atrial fibrillation is an extremely common cardiovascular pathology and is present in about one-third of patients admitted to our clinic. Cardiovascular diseases such as hypertension, ischemic coronary artery disease, and valvulopathy are common in patients with AF. Patients with AF are usually elderly patients with many associated diseases in whom sinus rhythm restoration treatment and anticoagulant therapy are difficult to establish. AF is one of the most common arrhythmias that complicates the evolution of acute myocardial infarction, association between dual antiplatelet therapy and anticoagulation treatment, increasing the risk of bleeding complications.&#x0D; Conclusions: Atrial fibrillation is an extremely common cardiovascular pathology and is present in about one-third of patients admitted to our hospital. The data obtained revealed that this arrhythmia occurs in a small number of cases as the only pathology of the patient, usually associated with numerous comorbidities. Cardiovascular diseases such as hypertension, ischemic coronary artery disease, valvulopathy are common in our practice. Patient with AF is a patient who requires long-term anticoagulant therapy and in whom sinus rhythm recovery therapy is dependent on the precocity of presentation to the physician, as well as on the therapeutic resources of current medicine.

Overexpression of Perilipin 2 Induces Cardiac Steatosis and Atrial Fibrillation via Connexin 43 Remodeling

Atrial fibrillation (AF) is prevalent among diabetic patients. Diabetes is also associated with myocardial lipid droplet accumulation (steatosis), which is thought to be a source of intracellular lipotoxicity. Since the relative contribution of cardiac steatosis per se to AF has not been elucidated, the current study was designed to clarify the causal effect of cardiac steatosis on AF using an aged mouse model of cardiac steatosis. Cardiac-specific perilipin (PLIN) 2-overexpressing mice (PLIN2-Tg) were created and maintained on a chow diet for &amp;gt;12 months. Cardiac steatosis was assessed by electron microscopy and triacylglycerol (TAG) content. AF was induced by transesophageal electrical burst pacing, and the duration of AF was measured. Atrial impulse conduction patterns were analyzed in Langendorff-perfused hearts using optical mapping technique. Myocardial localization of a gap junction protein, connexin (Cx) 43, was analyzed by confocal microscopy. Electron microscopy of the atrium of PLIN2-Tg revealed accumulation of small lipid droplets around clusters of mitochondria, and the atrial TAG content in PLIN2-Tg was 4- to 8-fold higher than that in wild type (Wt) atrium. Electrocardiograms showed significantly longer RR intervals in PLIN2-Tg compared to Wt mice. The prevalence of sustained (&amp;gt;5min) AF was significantly greater in PLIN2-Tg compared with Wt mice (69% vs. 24%). Confocal microscopy revealed that Cx43 was distributed at the intercalated discs in Wt atria, whereas it was heterogeneously redistributed to the lateral side of the cardiomyocytes in PLIN2-Tg atria. Isochrone mapping showed slow and heterogeneous impulse propagation in PLIN2-Tg atria compared with Wt atria. These results indicate that PLIN2-induced steatosis causes Cx43 remodeling, impaired conduction propagation, and a higher incidence of AF. Controlling cardiac steatosis might be an important target for inhibiting AF in patients with cardiac steatosis. Disclosure S. Sato: None. J. Suzuki: None. M. Hirose: None. T. Nakaya: None. M. Yamada: None. M. Ichikawa: None. M. Imagawa: None. Y. Zenimaru: None. S. Takahashi: None. F.B. Kraemer: None. T. Konoshita: None. T. Ishizuka: None.

Atrial fibrillation in dialysis patients: is there a place for non-vitamin K antagonist oral anticoagulants?

Atrial fibrillation (AF) occurs approximately in 3% of general population, with greater prevalence in elderly. Non-vitamin K-dependent oral anticoagulant agents (NOACs) according to the current European guidelines are recommended for patients with AF at high risk for stroke as a first-choice treatment. NOACs are not inferior to warfarin or some of them are better than warfarin in reducing the rate of ischemic stroke. Moreover, they significantly reduce the rate of intracranial hemorrhages, major bleedings, and mortality compared with warfarin. Nevertheless according to ESC guidelines, NOACs are not recommended in patients with creatinine clearance < 30mL/min. Observational studies provide contradictive data. Only few new trials are ongoing. Therefore, it is not clear if NOACs should be in the future prescribed to patients with advanced CKD and those on dialysis. Moreover, the risk of stroke and bleeding is much higher in such population than in patients without end-stage renal disease (ESRD). The authors provide data on pros and cons of use of NOACs in ESRD patients with AF.

Managing atrial fibrillation to prevent stroke

Atrial fibrillation (AF) is an important risk factor of stroke and contributes to 20% of strokes in the UK; however, with appropriate intervention, the risk can be reversed. For patients with a diagnosis of non-valvular atrial fibrillation, therapeutic anticoagulation is the treatment of choice. The National Institute for Health and Care Excellence AF guidelines recommend that every patient should receive appropriate treatment and a personalised package of care; empowering them to take ownership of their healthcare needs and make informed and educated decisions about their health. However, there are still a significant proportion of patients that are not receiving effective therapeutic treatment. This article explores the current best practice requirements for AF stroke prevention, considering clinical need for diagnosis; individualised risk assessment for appropriate treatment; progress in anticoagulation options; and delivery of a patient-centred package of care in today's practice.

Tailored Anticoagulation for Thromboembolic Risk Reduction in Paroxysmal Atrial Fibrillation.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting up to six million people in the United States and more than 35 million individuals worldwide. Thromboembolism, including stroke, represents the most common AF-related morbidity and mortality and data indicate that anticoagulation can mitigate this risk by 65%. Our understanding of thromboembolism in AF, however, remains incomplete, and the mechanisms by which AF increases thromboembolic risk are areas of ongoing investigation and debate. Current guidelines do not differentiate between the frequency and duration of AF episodes (AF burden) when selecting which patients with AF should be treated with anticoagulation for thromboembolic risk reduction. Recent data, primarily using cardiac implantable electronic devices (CIEDs) such as pacemakers, implantable cardioverter-defibrillators, and implantable loop recorders, however, have challenged this longstanding notion that AF burden does not influence thromboembolic risk. Continuous and automated cardiac rhythm monitoring via CIEDs with accurate and rapid acquisition and transmission of rhythm data also affords the opportunity to study the relationship between AF burden and thromboembolism and novel ways to reduce thromboembolic risk while minimizing the risk associated with chronic anticoagulation use. This manuscript will review the associations between subclinical, CIED-detected atrial arrhythmias and thromboembolic events. It will also discuss the emergence of “tailored anticoagulation,” an anticoagulation strategy wherein CIEDs and remote AF monitoring are employed to allow dynamic administration of oral anticoagulation only around episodes of AF, and the holding of anticoagulation during prolonged periods of sinus rhythm when the thromboembolic risk associated with AF is presumably very low.