Catheter Ablation for Atrial Fibrillation in Adult Congenital Heart Disease: An International Multicenter Registry Study.

Background: Data on atrial fibrillation (AF) ablation and outcomes are limited in patients with congenital heart disease (CHD). We aimed to investigate the characteristics of patients with CHD presenting for AF ablation and their outcomes.

Methods: A multicenter, retrospective analysis was performed of patients with CHD undergoing AF ablation between 2004 and 2020 at 13 participating centers.

Electrical Substrate Ablation for Refractory Ventricular Fibrillation: Results of the AVATAR Study.

[Figure: see text].

Pulmonary Vein Stenosis and Pulmonary Hypertension Following a Catheter-Based Radiofrequency Ablation for Atrial Fibrillation: A Case Report.

BACKGROUND Pulmonary vein (PV) stenosis is a rare condition characterized by progressive luminal size reduction of one or more pulmonary veins (PVs), which can increase postcapillary pressure resulting in shortness of breath, cough, hemoptysis, and pulmonary hypertension (PH). The diagnosis of PV stenosis requires a high degree of suspicion. PV stenosis is a rare but recognized complication of catheter-based radiofrequency ablation (RFA) for atrial fibrillation (AF).

Extended cardiac ambulatory rhythm monitoring in adults with congenital heart disease: Arrhythmia detection and impact of extended monitoring.

Background: Arrhythmias are a leading cause of death in adults with congenital heart disease (ACHD). While 24-48-hour monitors are often used to assess arrhythmia burden, extended continuous ambulatory rhythm monitors (ECAM) can record 2 weeks of data. The utility of this device and the arrhythmia burden identified beyond 48-hour monitoring have not been evaluated in the ACHD population.

Clinical Implications of Ablation of Drivers for Atrial Fibrillation: A Systematic Review and Meta-Analysis.

Background: The outcomes from pulmonary vein isolation (PVI) for atrial fibrillation (AF) are suboptimal, but the benefits of additional lesion sets remain unproven. Recent studies propose ablation of AF drivers improves outcomes over PVI, yet with conflicting reports in the literature. We undertook a systematic literature review and meta-analysis to determine outcomes from ablation of AF drivers in addition to PVI or as a stand-alone procedure.

Identification and Characterization of Sites Where Persistent Atrial Fibrillation Is Terminated by Localized Ablation.

Background: The mechanisms by which persistent atrial fibrillation (AF) terminates via localized ablation are not well understood. To address the hypothesis that sites where localized ablation terminates persistent AF have characteristics identifiable with activation mapping during AF, we systematically examined activation patterns acquired only in cases of unequivocal termination by ablation.

Methods And Results: We recruited 57 patients with persistent AF undergoing ablation, in whom localized ablation terminated AF to sinus rhythm or organized tachycardia.

Radiation Safety in Children With Congenital and Acquired Heart Disease: A Scientific Position Statement on Multimodality Dose Optimization From the Image Gently Alliance.

There is a need for consensus recommendations for ionizing radiation dose optimization during multimodality medical imaging in children with congenital and acquired heart disease (CAHD). These children often have complex diseases and may be exposed to a relatively high cumulative burden of ionizing radiation from medical imaging procedures, including cardiac computed tomography, nuclear cardiology studies, and fluoroscopically guided diagnostic and interventional catheterization and electrophysiology procedures. Although these imaging procedures are all essential to the care of children with CAHD and have contributed to meaningfully improved outcomes in these patients, exposure to ionizing radiation is associated with potential risks, including an increased lifetime attributable risk of cancer.

Multicentre safety of adding Focal Impulse and Rotor Modulation (FIRM) to conventional ablation for atrial fibrillation.

Aims: Focal Impulse and Rotor Modulation (FIRM) uses 64-electrode basket catheters to identify atrial fibrillation (AF)-sustaining sites for ablation, with promising results in many studies. Accordingly, new basket designs are being tested by several groups. We set out to determine the procedural safety of adding basket mapping and map-guided ablation to conventional pulmonary vein isolation (PVI).

The precise timing of tachycardia entrainment is determined by the postpacing interval, the tachycardia cycle length, and the pacing rate: Theoretical insights and practical applications.

Background: Previous observations have reported that the number of pacing stimuli required to entrain a tachycardia varies on the basis of arrhythmia type and location, but a quantitative formulation of the number needed to entrain (NNE) that unifies these observations has not been characterized.

Objective: We sought to investigate the relationship between the number of pacing stimulations, the tachycardia cycle length (TCL), the overdrive pacing cycle length (PCL), and the postpacing interval (PPI) to accurately estimate the timing of tachycardia entrainment.

Methods: First, we detailed a mathematical derivation unifying electrophysiological parameters with empirical confirmation in 2 patients undergoing catheter ablation of typical atrial flutter.

Current and emerging antiarrhythmic drug therapy for ventricular tachycardia.

Ventricular arrhythmias, including ventricular fibrillation (VF) and sustained ventricular tachycardia (VT), are the principal causes of sudden cardiac death in patients with structural heart disease. While coronary artery disease is the predominant substrate associated with the development of VT, these arrhythmias are known to occur in a variety of disorders, including dilated cardiomyopathy, valvular and congenital heart disease, and cardiac ion channelopathies such as the long QT syndrome. In a minority of patients, VT occurs in the absence of structural heart disease.

Diagnosis and ablation of multiform fascicular tachycardia.

Introduction: Fascicular tachycardia (FT) is an uncommon cause of monomorphic sustained ventricular tachycardia (VT). We describe 6 cases of FT with multiform QRS morphologies.

Methods And Results: Six of 823 consecutive VT cases were retrospectively analyzed and found attributable to FT with multiform QRS patterns, with 3 cases exhibiting narrow QRS VT as well.

Ictal asystole: an indication for pacemaker implantation and emerging cause of sudden death.

Ictal asystole is being recognized as a potential mechanism of sudden unexplained death in epilepsy (SUDEP). We report a case of a patient without known cardiac disease presenting with ictal asystole resulting in syncope, trauma, and need for pacemaker implantation. The management of ictal asystole is also briefly reviewed.

Acute Antiarrhythmic Therapy of Ventricular Tachycardia and Ventricular Fibrillation.

Ventricular arrhythmias (ventricular tachycardia and ventricular fibrillation) are often associated with underlying structural heart disease and require prompt assessment and treatment. Acute treatment involves initial hemodynamic stabilization of the patient followed by suppressive treatment with pharmacologic and nonpharmacologic approaches for reducing the risk of recurrence of ventricular arrhythmias and potential development of sudden cardiac death. This article reviews acute antiarrhythmic drug therapy for ventricular arrhythmias based on the clinical presentation.

Narrow Complex Tachycardia: What is the Mechanism?

This article reports an interesting case of a narrow complex tachycardia presenting the diagnostic dilemma of differentiating atrioventricular nodal reentrant tachycardia (AVNRT) from junctional tachycardia. It proposes delivering late-coupled premature atrial complexes during the tachycardia with short ventriculo-atrial interval as a diagnostic maneuver to differentiate AVNRT from junctional tachycardia in the electrophysiology laboratory. Treatments of these arrhythmias vary, and making the appropriate diagnosis of supraventricular tachycardia is essential to providing effective arrhythmia management.

Injection of bone marrow cell extract into infarcted hearts results in functional improvement comparable to intact cell therapy.

We compared therapeutic benefits of intramyocardial injection of unfractionated bone marrow cells (BMCs) versus BMC extract as treatments for myocardial infarction (MI), using closed-chest ultrasound-guided injection at a clinically relevant time post-MI. MI was induced in mice and the animals treated at day 3 with either: (i) BMCs from green fluorescent protein (GFP)-expressing mice (n = 14), (ii) BMC extract (n = 14), or (iii) saline control (n = 14). Six animals per group were used for histology at day 6 and the rest followed to day 28 for functional analysis.

Pharmacological therapy for atrial fibrillation: current options and new agents.

Atrial fibrillation is the most commonly encountered cardiac arrhythmia and is directly or indirectly responsible for considerable mortality, morbidity and health care burden. The available medical therapy is limited by marginal efficacy, end-organ toxicity, as well as the potential for undesired ventricular proarrhythmia. Elucidation of the potential mechanisms that underlie the development of atrial fibrillation may provide new targets for drugs that circumvent the problems associated with current medical options.