WITHDRAWN: Impact of Racial Differences on the Epidemiology and Clinical Outcomes of Atrial Fibrillation.

Unlabelled: Since the authors are not responding to the editor’s requests to fulfill the editorial requirement, therefore, the article has been withdrawn by the publisher. Bentham Science apologizes to the readers of the journal for any inconvenience this may have caused. The Bentham Editorial Policy on Article Withdrawal can be found at https://benthamscience.

Spatial concentration and distribution of phase singularities in human atrial fibrillation: Insights for the AF mechanism.

Background: Atrial fibrillation (AF) is characterized by the repetitive regeneration of unstable rotational events, the pivot of which are known as phase singularities (PSs). The spatial concentration and distribution of PSs have not been systematically investigated using quantitative statistical approaches.

Objectives: We utilized a geospatial statistical approach to determine the presence of local spatial concentration and global clustering of PSs in biatrial human AF recordings.

Peptidomics of enteroendocrine cells and characterisation of potential effects of a novel preprogastrin derived-peptide on glucose tolerance in lean mice.

Objectives: To analyse the peptidomics of mouse enteroendocrine cells (EECs) and human gastrointestinal (GI) tissue and identify novel gut derived peptides.

Methods: High resolution nano-flow liquid chromatography mass spectrometry (LC-MS/MS) was performed on (i) flow-cytometry purified NeuroD1 positive cells from mouse and homogenised human intestinal biopsies, (ii) supernatants from primary murine intestinal cultures, (iii) intestinal homogenates from mice fed high fat diet. Candidate bioactive peptides were selected on the basis of species conservation, high expression/biosynthesis in EECs and evidence of regulated secretionin vitro.

Atrial fibrosis and substrate based characterization in atrial fibrillation: Time to move forwards.

Atrial fibrillation (AF) is the most commonly encountered cardiac arrhythmia in clinical practice. However, current therapeutic interventions for atrial fibrillation have limited clinical efficacy as a consequence of major knowledge gaps in the mechanisms sustaining atrial fibrillation. From a mechanistic perspective, there is increasing evidence that atrial fibrosis plays a central role in the maintenance and perpetuation of atrial fibrillation.

M/M/Infinity Birth-Death Processes - A Quantitative Representational Framework to Summarize and Explain Phase Singularity and Wavelet Dynamics in Atrial Fibrillation.

Rationale: A quantitative framework to summarize and explain the quasi-stationary population dynamics of unstable phase singularities (PS) and wavelets in human atrial fibrillation (AF) is at present lacking. Building on recent evidence showing that the formation and destruction of PS and wavelets in AF can be represented as renewal processes, we sought to establish such a quantitative framework, which could also potentially provide insight into the mechanisms of spontaneous AF termination.

Objectives: Here, we hypothesized that the observed number of PS or wavelets in AF could be governed by a common set of renewal rate constants λ (for PS or wavelet formation) and λ (PS or wavelet destruction), with steady-state population dynamics modeled as an M/M/∞ birth-death process.

Atrial fibrillation burden: an update-the need for a CHA2DS2-VASc-AFBurden score.

Atrial fibrillation (AF) is an established independent risk factor for stroke. Current guidelines regard AF as binary; either present or absent, with the decision for anti-coagulation driven by clinical variables alone. However, there are increasing data to support a biological gradient of AF burden and stroke risk, both in clinical and non-clinical AF phenotypes.

Prospective cross-sectional study using Poisson renewal theory to study phase singularity formation and destruction rates in atrial fibrillation (RENEWAL-AF): Study design.

Background: Unstable functional reentrant circuits known as rotors have been consistently observed in atrial fibrillation and are mechanistically believed critical to the maintenance of the arrhythmia. Recently, using a Poisson renewal theory-based quantitative framework, we have demonstrated that rotor formation (λ) and destruction rates (λ) can be measured using in vivo electrophysiologic data. However, the association of λ and λ with clinical, electrical, and structural markers of atrial fibrillation phenotype is unknown.

Effectiveness of Wearable Trackers on Physical Activity in Healthy Adults: Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Background: Wearable trackers are an increasingly popular tool among healthy adults and are used to facilitate self-monitoring of physical activity.

Objective: We aimed to systematically review the effectiveness of wearable trackers for improving physical activity and weight reduction among healthy adults.

Methods: This review used the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology and reporting criteria.

Multipolar mapping with the high-density grid catheter compared with conventional point-by-point mapping to guide catheter ablation for focal arrhythmias.

Background: Multipolar catheters provide high-density mapping which may reduce the procedural duration and improve the success of catheter ablation (CA) for focal arrhythmias. The high-density grid (HDG) catheter is a 16 electrode mapping catheter with bipole recordings at orthogonal splines. The aim of this study is to compare the clinical and procedural features from a cohort who underwent CA for focal arrhythmias using multipolar mapping (MPM) with age and case-matched cohort using point-by-point (PbyP) mapping.

Position Statement on the Management of Cardiac Electrophysiology and Cardiac Implantable Electronic Devices in Australia During the COVID-19 Pandemic: A Living Document.

The COVID-19 pandemic poses a significant stress on health resources in Australia. The Heart Rhythm Council of the Cardiac Society of Australia and New Zealand aims to provide a framework for efficient resource utilisation balanced with competing risks when appropriately treating patients with cardiac arrhythmias. This document provides practical recommendations for the electrophysiology (EP) and cardiac implantable electronic devices (CIED) services in Australia.

Publisher Correction: Enhanced β-adrenergic signalling underlies an age-dependent beneficial metabolic effect of PI3K p110α inactivation in adipose tissue.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Hepatocyte p53 ablation induces metabolic dysregulation that is corrected by food restriction and vertical sleeve gastrectomy in mice.

P53 has been implicated in the pathogenesis of obesity and diabetes; however, the mechanisms and tissue sites of action are incompletely defined. Therefore, we investigated the role of hepatocyte p53 in metabolic homeostasis using a hepatocyte-specific p53 knockout mouse model. To gain further mechanistic insight, we studied mice under two complementary conditions of restricted weight gain: vertical sleeve gastrectomy (VSG) or food restriction.

Renewal Theory as a Universal Quantitative Framework to Characterize Phase Singularity Regeneration in Mammalian Cardiac Fibrillation.

Background: Despite a century of research, no clear quantitative framework exists to model the fundamental processes responsible for the continuous formation and destruction of phase singularities (PS) in cardiac fibrillation. We hypothesized PS formation/destruction in fibrillation could be modeled as self-regenerating Poisson renewal processes, producing exponential distributions of interevent times governed by constant rate parameters defined by the prevailing properties of each system.

Methods: PS formation/destruction were studied in 5 systems: (1) human persistent atrial fibrillation (n=20), (2) tachypaced sheep atrial fibrillation (n=5), (3) rat atrial fibrillation (n=4), (5) rat ventricular fibrillation (n=11), and (5) computer-simulated fibrillation.

Clinical safety of ProMRI implantable cardioverter-defibrillator systems during head and lower lumbar magnetic resonance imaging at 1.5 Tesla.

Magnetic resonance imaging (MRI) has long been contraindicated in patients with implanted pacemakers, defibrillators, and cardiac resynchronisation therapy (CRT) devices due to the risk of adverse effects through electromagnetic interference. Since many recipients of these devices will have a lifetime indication for an MRI scan, the implantable systems should be developed as 'MRI-conditional' (be safe for the MRI environment under predefined conditions). We evaluated the clinical safety of several Biotronik ProMRI ('MRI-conditional') defibrillator and CRT systems during head and lower lumbar MRI scans at 1.

Complications of cardiac implantable electronic device placement in public and private hospitals.

Background: Few safety data exist comparing clinical outcomes in Australian public and private hospitals. We hypothesised that differences could exist between public and private hospitals due to differences in acuity and patient-level co-morbidities.

Aims: To report comparative complications of cardiac implantable electronic device (CIED) placement in public and private hospitals.

Advanced Echocardiographic Imaging for Prediction of SCD in Moderate and Severe LV Systolic Function.

Objectives: This study sought to determine the long-term prognostic value of myocardial deformation imaging by echocardiography in risk stratification of sudden cardiac death (SCD) and malignant ventricular arrhythmias (VAs) in a large consecutive cohort of patients with left ventricular (LV) systolic impairment, irrespective of its etiology.

Background: Left ventricular ejection fraction (LVEF) is limited for prediction of SCD. Echocardiographic strain-derived mechanical dispersion (MD) and global longitudinal strain (GLS) has been linked to VA and SCD.

Is Atrial Fibrillation a Stroke Risk Factor or Risk Marker? An Appraisal Using the Bradford Hill Framework for Causality.

Atrial fibrillation (AF) is strongly associated with stroke risk but association on its own does not necessarily imply causality. Is AF a cause (risk factor) of stroke? Would treatment that reduces AF burden also reduce the burden of stroke? Or, perhaps, AF is a risk marker associated with a vascular syndrome in which there is co-existing atrial structural and electrical remodelling that results in the clinical manifestation of AF and the risk of stroke in parallel. A number of recent studies appear to detach AF as a direct cause of stroke.

Transcatheter Transseptal Mitral Valve-in-Valve Replacement: An Early Australian Case Series and Literature Review.

Background: Transcatheter mitral valve implantation for degenerated bioprostheses has recently emerged as an alternative to redo mitral valve surgery, particularly in patients at high risk for reoperative cardiac surgery. We sought to examine our early experience of transcatheter transseptal mitral valve-in-valve procedures.

Methods: Prospectively collected data was retrospectively reviewed in patients undergoing transcatheter transseptal mitral valve-in-valve implantation using the Edwards Sapien 3 balloon expandable bioprosthesis (Edwards Lifesciences, Irvine, CA, USA).

Comparative spatial resolution of 12-lead electrocardiography and an automated algorithm.

Background: The spatial resolution of pacemapping using 12-lead electrocardiography (ECG) or PaSo software is unknown.

Objective: The purpose of this study was to determine the spatial resolution of traditional ECG pacemapping and pacemapping using the PaSo coefficients.

Methods: Seventeen patients undergoing ablation of supraventricular tachycardias or atrioventricular node were included.

Endothelial dysfunction and glycocalyx shedding in heart failure: insights from patients receiving cardiac resynchronisation therapy.

To determine (a) whether chronic heart failure with reduced ejection fraction (HFrEF) is associated with increased glycocalyx shedding; (b) whether glycocalyx shedding in HFrEF with left ventricular dyssynchrony is related to inflammation, endothelial dysfunction and/or redox stress and is ameliorated by cardiac resynchronisation therapy. Glycocalyx shedding has been reported to be increased in heart failure and is a marker of increased mortality. Its role in dyssynchronous systolic heart failure and the effects of cardiac resynchronisation therapy (CRT) are largely unknown.

Institutional Variation in Quality of Cardiovascular Implantable Electronic Device Implantation: A Cohort Study.

Background: Cardiovascular implantable electronic devices (CIEDs) are associated with procedure-related complications, yet little is known about variation in complication rates among institutions that may suggest disparities in care quality.

Objective: To assess institutional variation in risk-standardized complication rates (RSCRs) for CIED.

Design: Cohort study.