The impact of common and rare genetic variants on bradyarrhythmia development.

To broaden our understanding of bradyarrhythmias and conduction disease, we performed common variant genome-wide association analyses in up to 1.3 million individuals and rare variant burden testing in 460,000 individuals for sinus node dysfunction (SND), distal conduction disease (DCD) and pacemaker (PM) implantation. We identified 13, 31 and 21 common variant loci for SND, DCD and PM, respectively.

Predictors of Success for Pulmonary Vein Isolation With Pulsed-field Ablation Using a Variable-loop Catheter With 3D Mapping Integration: Complete 12-month Outcomes From inspIRE.

Background: We previously presented the safety and early efficacy of the inspIRE study (Study for Treatment of Paroxysmal Atrial Fibrillation [PAF] by Pulsed-field Ablation [PFA] System With Irreversible Electroporation [IRE]). With the study's conclusion, we report the outcomes of the full pivotal study cohort, with an additional analysis of predictors of success.

Methods: InspIRE was a prospective, multicenter, single-arm clinical trial of drug-refractory paroxysmal atrial fibrillation.

Efficacy and safety of supraclavicular and pectoralis nerve blocks as primary peri-procedural analgesia for cardiac electronic device implantation: A pilot study.

Background: Cardiac implantable electronic devices (CIEDs) are routinely implanted using intravenous drugs for sedation. However, some patients are poor candidates for intravenous sedation.

Objective: We present a case series demonstrating the safety and efficacy of a novel, ultrasound-guided nerve block technique that allows for pre-pectoral CIED implantation.

Paroxysmal Atrial Fibrillation Ablation Using a Novel Variable-Loop Biphasic Pulsed Field Ablation Catheter Integrated With a 3-Dimensional Mapping System: 1-Year Outcomes of the Multicenter inspIRE Study.

Background: The inspIRE study (Study for Treatment of Paroxysmal Atrial Fibrillation [PAF] by Pulsed Field Ablation [PFA] System With Irreversible Electroporation [IRE]) evaluated safety and effectiveness of a fully integrated biphasic pulsed field ablation (PFA) system with a variable-loop circular catheter for the treatment of drug-refractory paroxysmal atrial fibrillation.

Methods: Subjects underwent pulmonary vein (PV) isolation with the PFA system, using at least 12 applications per vein; adenosine/isoproterenol was administered to confirm entrance block. Wave I assessed initial safety, including for esophageal lesions, silent cerebral lesions, and PV stenosis.

Progression of Atrial Fibrillation after Cryoablation or Drug Therapy.

Background: Atrial fibrillation is a chronic, progressive disorder, and persistent forms of atrial fibrillation are associated with increased risks of thromboembolism and heart failure. Catheter ablation as initial therapy may modify the pathogenic mechanism of atrial fibrillation and alter progression to persistent atrial fibrillation.

Methods: We report the 3-year follow-up of patients with paroxysmal, untreated atrial fibrillation who were enrolled in a trial in which they had been randomly assigned to undergo initial rhythm-control therapy with cryoballoon ablation or to receive antiarrhythmic drug therapy.

Is Maintenance of Sinus Rhythm of Value in Patients with Atrial Fibrillation and Heart Failure?

Purpose Of Review: Heart failure (HF) and atrial fibrillation (AF) frequently co-exist, with the prevalence of AF increasing in patients with more advanced HF symptoms. When present, AF increases morbidity and mortality in patients with HF. The purpose of this review is to examine emerging evidence addressing the value of restoration and maintenance of sinus rhythm in patients with HF.

Assessment of left atrial fibrosis progression in canines following rapid ventricular pacing using 3D late gadolinium enhanced CMR images.

Background: Atrial fibrillation (AF) is associated with extracellular matrix (ECM) remodelling and often coexists with myocardial fibrosis (MF); however, the causality of these conditions is not well established.

Objective: We aim to corroborate AF to MF causality by quantifying left atrial (LA) fibrosis in cardiac magnetic resonance (CMR) images after persistent rapid ventricular pacing and subsequent AF using a canine model and histopathological validation.

Methods: Twelve canines (9 experimental, 3 control) underwent baseline 3D LGE-CMR imaging at 3T followed by insertion of a pacing device and 5 weeks of rapid ventricular pacing to induce AF (experimental) or no pacing (control).

Randomized trial of conventional versus radiofrequency needle transseptal puncture for cryoballoon ablation: the CRYO-LATS trial.

Background: Transseptal puncture to achieve left atrial access is necessary for many cardiac procedures, including atrial fibrillation ablation. More recently, there has been an increasing need for left atrial access using large caliber sheaths, which increases risk of perforation associated with the initial advancement into the left atrium. We compared the effectiveness of a radiofrequency needle-based transseptal system versus conventional needle for transseptal access.

Hemodynamically Tolerated Ventricular Tachycardia With Mildly Impaired Ejection Fraction: Do These Patients Have VT/VF Recurrence and ICD Therapies?

Background: Patients with hemodynamically tolerated ventricular tachycardia (VT) and minimally reduced left ventricular ejection fraction (LVEF) remain a group that presents a prognostic and therapeutic dilemma.

Methods: We studied patients from our implanted cardioverter-defibrillator (ICD) database who received ICDs for hemodynamically tolerated VT and mildly reduced LVEF (36%-49%) at time of implant between May 2015 and December 2019. Time to appropriate ICD therapy was assessed.

Randomized Ablation-Based Rhythm-Control Versus Rate-Control Trial in Patients With Heart Failure and Atrial Fibrillation: Results from the RAFT-AF trial.

Background: Atrial fibrillation (AF) and heart failure (HF) frequently coexist and can be challenging to treat. Pharmacologically based rhythm control of AF has not proven to be superior to rate control. Ablation-based rhythm control was compared with rate control to evaluate if clinical outcomes in patients with HF and AF could be improved.

Safety of Lead Repair Compared to Lead Revision for Visible Lead Insulation Defects in Patients With Cardiac Implantable Electronic Devices.

Background: Cardiac implantable electronic devices deliver life-sustaining therapy and may be prone to hardware degeneration over time. Functioning transvenous endocardial leads with visible insulation breaks are amenable to lead revision (LRV) or lead repair (LRP), with medical adhesive. The latter is a less invasive and more cost-effective strategy.

Epigenetic Age and the Risk of Incident Atrial Fibrillation.

Background: The most prominent risk factor for atrial fibrillation (AF) is chronological age; however, underlying mechanisms are unexplained. Algorithms using epigenetic modifications to the human genome effectively predict chronological age. Chronological and epigenetic predicted ages may diverge in a phenomenon referred to as epigenetic age acceleration (EAA), which may reflect accelerated biological aging.

Evaluating Polygenic Risk Scores in "Lone" Atrial Fibrillation.

Background: Polygenic scores incorporating varying numbers of single nucleotide polymorphisms (SNPs) have been demonstrated to exert a prominent role in atrial fibrillation (AF). We sought to compare the relative discriminatory capacities of 2 previously validated polygenic scores in "lone" AF.

Methods: A total of 186 lone AF cases of European ancestry underwent SNP genotyping.

Surveillance for Outcomes Selected as Atrial Fibrillation Quality Indicators in Canada: 10-Year Trends in Stroke, Major Bleeding, and Heart Failure.

Background: Whether advances in identification and management of atrial fibrillation and atrial flutter (collectively, AF) have led to improved outcomes is unclear. We sought to study trends in clinical outcomes selected as quality indicators for nonvalvular AF in Canada.

Methods: We identified hospitalized patients with a first diagnosis of nonvalvular AF between April 2006 and March 2015, in all of Canada except Quebec.