Baseline quantitative ECG parameters do not fully predict class 1 antiarrhythmic effect in Brugada patient: Drug-induced ECG changes in Brugada patients.

Background: Drug challenge is useful to identify patients with Brugada syndrome (BS) without spontaneous ECG type 1 pattern. Effect of class I antiarrhythmic challenge is difficult to anticipate and potentially associated with complications.

Objective: Assess the response to class I antiarrhythmic challenge.

Making Sense of Missense: Benchmarking MutScore for Variant Interpretation in Inherited Cardiac Diseases.

Background: Accurate interpretation of genetic variants still represents a major challenge. According to current recommendations from the American College of Medical Genetics and Genomics (ACMG), variant interpretation relies on a comprehensive analysis including, among others, computational data for prediction of variant pathogenicity. However, the predictive accuracy of in silico tools is often limited, and results are frequently inconsistent.

Cardiopulmonary Fitness and Physical Activity Among Children and Adolescents With Inherited Cardiac Disease.

Importance: Historical restrictions on children with inherited cardiac arrhythmia or cardiomyopathy have been implemented to mitigate the potential risk of sudden death, but these limitations can be detrimental to overall health and cardiopulmonary fitness.

Objectives: To evaluate cardiopulmonary fitness and physical activity among children with inherited cardiac disease and identify the factors associated with maximum oxygen uptake (V̇o2max) in this population.

Design, Setting, And Participants: This cross-sectional, multicenter, prospective controlled study was conducted in 7 tertiary care expert centers for inherited cardiac disease in France from February 1, 2021, to June 20, 2023, with a 2-week follow-up.

An international multicenter cohort study on implantable cardioverter-defibrillators for the treatment of symptomatic children with catecholaminergic polymorphic ventricular tachycardia.

Background: Catecholaminergic polymorphic ventricular tachycardia (CPVT) may cause sudden cardiac death (SCD) despite medical therapy. Therefore, implantable cardioverter-defibrillators (ICDs) are commonly advised. However, there is limited data on the outcomes of ICD use in children.

Insights into adherence to medication and lifestyle recommendations in an international cohort of patients with catecholaminergic polymorphic ventricular tachycardia.

Aims: In patients with catecholaminergic polymorphic ventricular tachycardia (CPVT), a rare inherited arrhythmia syndrome, arrhythmic events can be prevented by medication and lifestyle recommendations. In patients who experience breakthrough arrhythmic events, non-adherence plays an essential role. We aimed to investigate the incidence and potential reasons for non-adherence to medication and lifestyle recommendations in a large, international cohort of patients with CPVT.

Type 3 long QT syndrome: Is the effectiveness of treatment with beta-blockers population-specific?

Background: The efficacy of beta-blocker treatment in type 3 long QT syndrome (LQT3) remains debated.

Objectives: The purpose of this study was to test the hypothesis that beta-blocker use is associated with cardiac events (CEs) in a French cohort of LQT3 patients.

Methods: All patients with a likely pathogenic/pathogenic variant in the SCN5A gene (linked to LQT3) were included and followed-up.

Flecainide Is Associated With a Lower Incidence of Arrhythmic Events in a Large Cohort of Patients With Catecholaminergic Polymorphic Ventricular Tachycardia.

Background: In severely affected patients with catecholaminergic polymorphic ventricular tachycardia, beta-blockers are often insufficiently protective. The purpose of this study was to evaluate whether flecainide is associated with a lower incidence of arrhythmic events (AEs) when added to beta-blockers in a large cohort of patients with catecholaminergic polymorphic ventricular tachycardia.

Methods: From 2 international registries, this multicenter case cross-over study included patients with a clinical or genetic diagnosis of catecholaminergic polymorphic ventricular tachycardia in whom flecainide was added to beta-blocker therapy.

Neurogenic hypertension characterizes children with congenital central hypoventilation syndrome and is aggravated by alveolar hypoventilation during sleep.

Objectives: Autonomic nervous system (ANS) dysfunction characterizes congenital central hypoventilation syndrome (CCHS). The objectives were to describe ambulatory blood pressure monitoring (ABPM) of children with CCHS, to assess cardiac ANS dysfunction as compared with control participants and to search for relationships between ANS dysfunction and blood pressure (BP) or night-time PCO 2 measurements.

Methods: Retrospective study of ABPM of children with CCHS and case (CCHS)-control (healthy children) study of heart rate variability (HRV) indices obtained during polysomnography (wakefulness, nonrapid eye movement sleep, rapid eye movement sleep, and whole night).

A need for exhaustive and standardized characterization of ion channels activity. The case of K11.1.

hERG, the pore-forming subunit of the rapid component of the delayed rectifier K current, plays a key role in ventricular repolarization. Mutations in the gene encoding hERG are associated with several cardiac rhythmic disorders, mainly the Long QT syndrome (LQTS) characterized by prolonged ventricular repolarization, leading to ventricular tachyarrhythmias, sometimes progressing to ventricular fibrillation and sudden death. Over the past few years, the emergence of next-generation sequencing has revealed an increasing number of genetic variants including variants.

Heart rate variability in congenital central hypoventilation syndrome: relationships with hypertension and sinus pauses.

Background: Autonomic nervous system (ANS) dysregulation has been described in congenital central hypoventilation syndrome (CCHS). The objectives were to describe heart rate variability (HRV) analyses in children suffering from CCHS both while awake and asleep and their relationships with both ambulatory blood pressure (BP) and ECG monitoring results.

Methods: This retrospective study enrolled children with CCHS (n = 33, median age 8.

Novel Variant Causing Calmodulinopathy With Variable Expressivity in a 4-Generation Family.

Background: CaM (calmodulin), encoded by 3 separate genes (, , and ), is a multifunctional Ca-binding protein involved in many signal transduction events including ion channel regulation. CaM variants may present with early-onset long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia, or sudden cardiac death. Most reported variants occurred de novo.

An International Multicenter Cohort Study on β-Blockers for the Treatment of Symptomatic Children With Catecholaminergic Polymorphic Ventricular Tachycardia.

Background: Symptomatic children with catecholaminergic polymorphic ventricular tachycardia (CPVT) are at risk for recurrent arrhythmic events. β-Blockers decrease this risk, but studies comparing individual β-blockers in sizeable cohorts are lacking. We aimed to assess the association between risk for arrhythmic events and type of β-blocker in a large cohort of symptomatic children with CPVT.

A standardised hERG phenotyping pipeline to evaluate KCNH2 genetic variant pathogenicity.

Background And Aims: Mutations in KCNH2 cause long or short QT syndromes (LQTS or SQTS) predisposing to life-threatening arrhythmias. Over 1000 hERG variants have been described by clinicians, but most remain to be characterised. The objective is to standardise and accelerate the phenotyping process to contribute to clinician diagnosis and patient counselling.

Challenging indication of cardioverter defibrillator implantation after sudden cardiac arrest in the very young: a case series of catecholaminergic polymorphic ventricular tachycardia secondary to calmodulin p.Asn98Ser.

Background: Calmodulinopathy is an emerging group of primary electrical disease with various, severe, and early onset phenotype. Sudden cardiac arrest (SCA)/death can be the first symptom and current medical management seems insufficient to prevent recurrences. Implantable cardioverter-defibrillator (ICD) in the young is challenging and can be harmful.

Computerized automated algorithm-based analyses of digitized paper ECGs in Brugada syndrome.

Background: Brugada syndrome is a rare inherited arrhythmic syndrome with a coved type 1 ST-segment elevation on ECG and an increased risk of sudden death. Many studies have evaluated risk stratification performance based on ECG-derived parameters. However, since historical Brugada patient cohorts included mostly paper ECGs, most studies have been based on manual ECG parameter measurements.

Mutation location and IKs regulation in the arrhythmic risk of long QT syndrome type 1: the importance of the KCNQ1 S6 region.

Aims: Mutation type, location, dominant-negative IKs reduction, and possibly loss of cyclic adenosine monophosphate (cAMP)-dependent IKs stimulation via protein kinase A (PKA) influence the clinical severity of long QT syndrome type 1 (LQT1). Given the malignancy of KCNQ1-p.A341V, we assessed whether mutations neighbouring p.

Deep learning analysis of electrocardiogram for risk prediction of drug-induced arrhythmias and diagnosis of long QT syndrome.

Aims: Congenital long-QT syndromes (cLQTS) or drug-induced long-QT syndromes (diLQTS) can cause torsade de pointes (TdP), a life-threatening ventricular arrhythmia. The current strategy for the identification of drugs at the high risk of TdP relies on measuring the QT interval corrected for heart rate (QTc) on the electrocardiogram (ECG). However, QTc has a low positive predictive value.