Clonal Hematopoiesis of Indeterminate Potential With Loss of Enhances Risk for Atrial Fibrillation Through Inflammasome Activation.

Background: Clonal hematopoiesis of indeterminate potential (CHIP), a common age-associated phenomenon, associates with increased risk of both hematological malignancy and cardiovascular disease. Although CHIP is known to increase the risk of myocardial infarction and heart failure, the influence of CHIP in cardiac arrhythmias, such as atrial fibrillation (AF), is less explored.

Methods: CHIP prevalence was determined in the UK Biobank, and incident AF analysis was stratified by CHIP status and clone size using Cox proportional hazard models.

A Lifestyle Modification Program for Secondary Prevention of Atrial Fibrillation: A Pilot Study.

Background: Lifestyle modification programs, such as cardiac rehabilitation, may reduce atrial fibrillation (AF) burden and improve quality of life (QOL), but remain unproven. The objective of this pilot study was to assess feasibility, acceptability, and preliminary effectiveness of an exercise and nutrition-based cardiac rehabilitation-like program for AF patients.

Methods: We enrolled overweight adults aged ≥ 30 years with symptomatic AF in a 12-week cardiac lifestyle group program, including 6 virtual and 6 in-person visits.

Loss of the Atrial Fibrillation-Related Gene, , Results in Atrial Dilation and Arrhythmias.

Background: (zinc finger homeobox 3), a gene that encodes a large transcription factor, is at the second-most significantly associated locus with atrial fibrillation (AF), but its function in the heart is unknown. This study aims to identify causative genetic variation related to AF at the locus and examine the impact of loss on cardiac function in mice.

Methods: CRISPR-Cas9 genome editing, chromatin immunoprecipitation, and luciferase assays in pluripotent stem cell-derived cardiomyocytes were used to identify causative genetic variation related to AF at the locus.

Recruited macrophages elicit atrial fibrillation.

Atrial fibrillation disrupts contraction of the atria, leading to stroke and heart failure. We deciphered how immune and stromal cells contribute to atrial fibrillation. Single-cell transcriptomes from human atria documented inflammatory monocyte and macrophage expansion in atrial fibrillation.

Genetic inhibition of serum glucocorticoid kinase 1 prevents obesity-related atrial fibrillation.

Obesity is an important risk factor for atrial fibrillation (AF), but a better mechanistic understanding of obesity-related atrial fibrillation is required. Serum glucocorticoid kinase 1 (SGK1) is a kinase positioned within multiple obesity-related pathways, and prior work has shown a pathologic role of SGK1 signaling in ventricular arrhythmias. We validated a mouse model of obesity-related AF using wild-type mice fed a high-fat diet.

Gate tunable light-matter interaction in natural biaxial hyperbolic van der Waals heterostructures.

The recent discovery of natural biaxial hyperbolicity in van der Waals crystals, such as -MoO, has opened up new avenues for mid-IR nanophotonics due to their deep subwavelength phonon polaritons. However, a significant challenge is the lack of active tunability of these hyperbolic phonon polaritons. In this work, we investigate heterostructures of graphene and -MoO for actively tunable hybrid plasmon phonon polariton modes via electrostatic gating in the mid-infrared spectral region.

Potential Gene Association Studies of Chemotherapy-Induced Cardiotoxicity: A Systematic Review and Meta-Analysis.

Chemotherapy is widely used in the treatment of cancer patients, but the cardiotoxicity induced by chemotherapy is still a major concern to most clinicians. Currently, genetic methods have been used to detect patients with high risk of chemotherapy-induced cardiotoxicity (CIC), and our study evaluated the correlation between genomic variants and CIC. The systematic literature search was performed in the PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), China Biology Medicine disc (CBMdisc), the Embase database, China National Knowledge Internet (CNKI) and Wanfang database from inception until June 2020.

Comparison between TightRail rotating dilator sheath and GlideLight laser sheath for transvenous lead extraction.

Background: There are limited data on the comparative analyses of TightRail rotating dilator sheath (Philips) and laser sheath for lead extraction.

Objective: To evaluate the effectiveness and safety of the TightRail sheath as a primary or secondary tool for transvenous lead extraction (TLE).

Methods: Retrospective cohort analysis of 202 consecutive patients who underwent TLE using either TightRail sheath and/or GlideLight laser sheath (Philips) in our hospital.

Use of the inverse solution guidance algorithm method for RF ablation catheter guidance.

Introduction: We previously introduced the inverse solution guidance algorithm (ISGA) methodology using a Single Equivalent Moving Dipole model of cardiac electrical activity to localize both the exit site of a re-entrant circuit and the tip of a radiofrequency (RF) ablation catheter. The purpose of this study was to investigate the use of ISGA for ablation catheter guidance in an animal model.

Methods: Ventricular tachycardia (VT) was simulated by rapid ventricular pacing at a target site in eleven Yorkshire swine.

Ibrutinib-Mediated Atrial Fibrillation Attributable to Inhibition of C-Terminal Src Kinase.

Background: Ibrutinib is a Bruton tyrosine kinase inhibitor with remarkable efficacy against B-cell cancers. Ibrutinib also increases the risk of atrial fibrillation (AF), which remains poorly understood.

Methods: We performed electrophysiology studies on mice treated with ibrutinib to assess inducibility of AF.

Stress-Induced Cardiomyopathy Secondary to COVID-19.

A 67-year-old female with prior medical history of HTN and asthma presented with acute-onset dyspnea and nausea for 4 days prior to admission. Upon initial encounter in the emergency room, she was found to have findings of abnormal pulmonary infiltrates and consequent workup revealed COVID-19. During further hospital course, the patient developed abnormal EKG and echocardiographic findings consistent with stress-induced cardiomyopathy.

Animal Models of Atrial Fibrillation.

Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in humans and is a significant source of morbidity and mortality. Despite its prevalence, our mechanistic understanding is incomplete, the therapeutic options have limited efficacy, and are often fraught with risks. A better biological understanding of AF is needed to spearhead novel therapeutic avenues.

A Miniaturized, Programmable Pacemaker for Long-Term Studies in the Mouse.

Rationale: Cardiac pacing is a critical technology for the treatment of arrhythmia and heart failure. The impact of specific pacing strategies on myocardial function is an area of intense research and high clinical significance. Mouse models have proven extremely useful for probing mechanisms of heart disease, but there is currently no reliable technology for long-term pacing in the mouse.

Genomic basis of atrial fibrillation.

Atrial fibrillation (AF) is a prevalent arrhythmia associated with substantial morbidity, mortality and costs. Available management strategies generally have limited efficacy and are associated with potential adverse effects. In part, the limited efficacy of approaches to managing AF reflect an incomplete understanding of the biological mechanisms underlying the arrhythmia, and only a partial understanding of how best to individualise management.

Connexin43 contributes to electrotonic conduction across scar tissue in the intact heart.

Studies have demonstrated non-myocytes, including fibroblasts, can electrically couple to myocytes in culture. However, evidence demonstrating current can passively spread across scar tissue in the intact heart remains elusive. We hypothesize electrotonic conduction occurs across non-myocyte gaps in the heart and is partly mediated by Connexin43 (Cx43).

Increased susceptibility of spontaneously hypertensive rats to ventricular tachyarrhythmias in early hypertension.

Hypertension is a risk factor for sudden cardiac death caused by ventricular tachycardia and fibrillation (VT/VF). We hypothesized that, in early hypertension, the susceptibility to stress-induced VT/VF increases. We compared the susceptibility of 5- to 6-month-old male spontaneously hypertensive rats (SHR) and age/sex-matched normotensive rats (NR) to VT/VF during challenge with oxidative stress (H2 O2 ; 0.

Molecular Basis of Hypokalemia-Induced Ventricular Fibrillation.

Background: Hypokalemia is known to promote ventricular arrhythmias, especially in combination with class III antiarrhythmic drugs like dofetilide. Here, we evaluated the underlying molecular mechanisms.

Methods And Results: Arrhythmias were recorded in isolated rabbit and rat hearts or patch-clamped ventricular myocytes exposed to hypokalemia (1.

Relation of Physical Activity and Incident Atrial Fibrillation (from the Multi-Ethnic Study of Atherosclerosis).

Previous studies have raised the question of whether an association exists between physical activity and atrial fibrillation (AF). We used the Multi-Ethnic Study of Atherosclerosis (MESA) database to examine the association between physical activity and AF in a diverse population without clinically recognized cardiovascular disease (CVD). MESA participants (n = 5,793) with complete baseline physical activity and covariate data were included.

Enhanced sensitivity of aged fibrotic hearts to angiotensin II- and hypokalemia-induced early afterdepolarization-mediated ventricular arrhythmias.

Unlike young hearts, aged hearts are highly susceptible to early afterdepolarization (EAD)-mediated ventricular fibrillation (VF). This differential may result from age-related structural remodeling (fibrosis) or electrical remodeling of ventricular myocytes or both. We used optical mapping and microelectrode recordings in Langendorff-perfused hearts and patch-clamp recordings in isolated ventricular myocytes from aged (24-26 mo) and young (3-4 mo) rats to assess susceptibility to EADs and VF during either oxidative stress with ANG II (2 μM) or ionic stress with hypokalemia (2.

Spontaneous ventricular fibrillation in right ventricular failure secondary to chronic pulmonary hypertension.

Background: Right ventricular failure (RVF) in pulmonary hypertension (PH) is associated with increased incidence of sudden death by a poorly explored mechanism. We test the hypothesis that PH promotes spontaneous ventricular fibrillation (VF) during a critical post-PH onset period characterized by a sudden increase in mortality.

Methods And Results: Rats received either a single subcutaneous dose of monocrotaline (MCT, 60 mg/kg) to induce PH-associated RVF (PH, n=24) or saline (control, n=17).

Glycolytic inhibition causes spontaneous ventricular fibrillation in aged hearts.

Selective glycolytic inhibition (GI) promotes electromechanical alternans and triggered beats in isolated cardiac myocytes. We sought to determine whether GI promotes triggered activity by early afterdepolarization (EAD) or delayed afterdepolarizations in intact hearts isolated from adult and aged rats. Dual voltage and intracellular calcium ion (Ca(i)(2+)) fluorescent optical maps and single cell glass microelectrode recordings were made from the left ventricular (LV) epicardium of isolated Langendorff-perfused adult (∼4 mo) and aged (∼24 mo) rat hearts.