Novel risk predictor of arrhythmias for patients with potassium channel-related congenital long QT syndrome.

Background: Congenital long QT syndrome (LQTS) is characterized by delayed ventricular repolarization, predisposing to potentially lethal ventricular arrhythmias. The variability in disease severity among patients remains largely unexplored, underscoring the limitations of current risk stratification methods.

Objective: We aimed to evaluate the potential utility of electrocardiographic markers from the exercise stress test (EST) in identifying patients with high-risk LQTS.

Long-term prognosis of patients with an SCN5A loss-of-function variant and progressive cardiac conduction disorder or Brugada syndrome.

Background: The long-term prognosis of patients with a loss-of-function variant in the cardiac sodium channel gene SCN5A is unknown.

Objective: This study aimed to evaluate the long-term arrhythmic risk in patients with an SCN5A loss-of-function variant to identify predictors of arrhythmic events.

Methods: Probands and family members with (likely) pathogenic SCN5A loss-of-function variants were retrospectively included.

Description of the Two-Dimensional Layer-Specific Strain Echocardiography Phenotype of Arrhythmogenic Left Ventricular Cardiomyopathy.

Background: Arrhythmogenic left ventricular cardiomyopathy (ALVC) is characterized by fibrofatty myocardial replacement demonstrated on cardiac magnetic resonance by late gadolinium enhancement (LGE) mainly involving the subepicardium. The aims of this study were to describe the layer-specific strain (LSS) echocardiography phenotype of ALVC and to compare it with LGE features.

Methods: All consecutive ALVC pathogenic genetic variant carriers and noncarrier relatives were separated into four prespecified groups (overt ALVC [group 1], isolated LGE [group 2], pathogenic genetic variant carrier without ALVC phenotype [group 3], and no genetic variant carrier [group 4]) and studied accordingly using cardiac magnetic resonance and LSS echocardiography.

Burden of rare variants in arrhythmogenic cardiomyopathy with right dominant form-associated genes provides new insights for molecular diagnosis and clinical management.

Arrhythmogenic cardiomyopathy with right dominant form (ACR) is a rare heritable cardiac cardiomyopathy disorder associated with sudden cardiac death. Pathogenic variants (PVs) in desmosomal genes have been causally related to ACR in 40% of cases. Other genes encoding nondesmosomal proteins have been described in ACR, but their contribution in this pathology is still debated.

Outcome of patients with early repolarization pattern and syncope.

Background: Syncope in patients with an early repolarization (ER) pattern presents a challenge for clinicians as it has been identified as an indicator of a higher risk of life-threatening ventricular arrhythmias (VAs).

Objectives: This study aimed to analyze the outcome of patients with an ER pattern and syncope and to evaluate the factors predictive of VAs.

Methods: Over a period of 5 years, we enrolled 143 patients with an ER pattern and syncope in a multicenter prospective registry.

Dose response to nadolol in congenital long QT syndrome.

Background: Beta-blocker therapy is the cornerstone of treatment for patients with long QT syndrome (LQTS). Few details on the dose to be used are available. As the response is variable between patients, we systematically evaluated the effect of treatment by performing an exercise test.

Replacement Myocardial Fibrosis in Patients With Mitral Valve Prolapse: Relation to Mitral Regurgitation, Ventricular Remodeling, and Arrhythmia.

Background: Mitral valve prolapse (MVP) is a frequent disease that can be complicated by mitral regurgitation (MR), heart failure, arterial embolism, rhythm disorders, and death. Left ventricular (LV) replacement myocardial fibrosis, a marker of maladaptive remodeling, has been described in patients with MVP, but the implications of this finding remain scarcely explored. We aimed at assessing the prevalence, pathophysiological and prognostic significance of LV replacement myocardial fibrosis through late gadolinium enhancement (LGE) by cardiac magnetic resonance in patients with MVP.

Robustness and relevance of predictive score in sudden cardiac death for patients with Brugada syndrome.

Aims: Risk stratification of sudden cardiac arrest (SCA) in Brugada syndrome (Brs) remains the main challenge for physicians. Several scores have been suggested to improve risk stratification but never replicated. We aim to investigate the accuracy of the Brs risk scores.

Familial screening in case of acute myocarditis reveals inherited arrhythmogenic left ventricular cardiomyopathies.

Aims: Several data suggest that acute myocarditis could be related to genetic variants involved in familial cardiomyopathies, particularly arrhythmogenic cardiomyopathy, but the management of patients with acute myocarditis and their families regarding their risk for having an associated inherited cardiomyopathy is unclear.

Methods And Results: Families with at least one individual with a documented episode of acute myocarditis and at least one individual with a cardiomyopathy or a history of sudden death were included in the study. Comprehensive pedigree, including genetic testing, and history of these families were analysed.

Age at diagnosis of Brugada syndrome: Influence on clinical characteristics and risk of arrhythmia.

Background: Despite a strong genetic background, Brugada syndrome (BrS) mainly affects middle-age patients. Data are scarce in the youngest and oldest age groups.

Objective: The purpose of this study was to describe the clinical characteristics and variations in rhythmic risk in BrS patients according to age.

Number of electrocardiogram leads in the diagnosis of spontaneous Brugada syndrome.

Background: The recently recommended single lead-based criterion for the diagnosis of Brugada syndrome may lead to overdiagnosis of this disorder and overestimation of the risk of sudden cardiac death.

Aim: To investigate the value of a single-lead diagnosis in patients with Brugada syndrome and a spontaneous type 1 electrocardiogram.

Methods: Consecutive patients with Brugada syndrome were included in a multicentre prospective registry; only those with a spontaneous type 1 electrocardiogram were enrolled.

Clinical presentation and follow-up of women affected by Brugada syndrome.

Background: Studies in Brugada syndrome (BrS) have mainly consisted of men.

Objective: The purpose of this study was to describe the clinical characteristics and arrhythmic risk factors in BrS women.

Methods: Consecutive BrS patients were enrolled from 1993 and followed prospectively.

Mental stress test: a rapid, simple, and efficient test to unmask long QT syndrome.

Aims: QT prolongation during mental stress test (MST) has been associated with familial idiopathic ventricular fibrillation. In long QT syndrome (LQTS), up to 30% of mutation carriers have normal QT duration. Our aim was to assess the QT response during MST, and its accuracy in the diagnosis of concealed LQTS.

Clinical Yield of Familial Screening After Sudden Death in Young Subjects: The French Experience.

Background: After sudden cardiac death with negative autopsy, clinical screening of relatives identifies a high proportion of inherited arrhythmia syndrome. However, the efficacy of this screening in families not selected by autopsy has never been assessed. We aim to investigate the value of clinical screening in relatives of all subjects who died suddenly before 45 years of age.

Progressive Atrial Conduction Defects Associated With Bone Malformation Caused by a Connexin-45 Mutation.

Background: Inherited cardiac conduction disease is a rare bradyarrhythmia associated with mutations in various genes that affect action potential propagation. It is often characterized by isolated conduction disturbance of the His-Purkinje system, but it is rarely described as a syndromic form.

Objectives: The authors sought to identify the genetic defect in families with a novel bradyarrhythmia syndrome associated with bone malformation.

Sodium-channel blocker challenge in the familial screening of Brugada syndrome: Safety and predictors of positivity.

Background: Sodium-channel blocker challenge (SCBC) is frequently performed to unmask Brugada syndrome.

Objective: We aim to identify predictors of positivity and complications of SCBC in the setting of familial screening of Brugada syndrome.

Methods: All consecutive patients from 2000 to 2014 who benefit from a sodium-channel blocker and belong to a family with at least 2 subjects affected by the syndrome were enrolled and followed prospectively.

Brugada syndrome: Diagnosis, risk stratification and management.

Brugada syndrome is a rare inherited arrhythmia syndrome leading to an increased risk of sudden cardiac death, despite a structurally normal heart. Diagnosis is based on a specific electrocardiogram pattern, observed either spontaneously or during a sodium channel blocker test. Among affected patients, risk stratification remains a challenge, despite recent insights from large population cohorts.

The Brugada Syndrome: A Rare Arrhythmia Disorder with Complex Inheritance.

For the last 10 years, applying new sequencing technologies to thousands of whole exomes has revealed the high variability of the human genome. Extreme caution should thus be taken to avoid misinterpretation when associating rare genetic variants to disease susceptibility. The Brugada syndrome (BrS) is a rare inherited arrhythmia disease associated with high risk of sudden cardiac death in the young adult.

Prognostic significance of fever-induced Brugada syndrome.

Background: In Brugada syndrome (BrS), spontaneous type 1 electrocardiogram (ECG) is an established risk marker for fatal arrhythmias whereas drug-induced type 1 ECG shows a relatively benign prognosis. No study has analyzed the prognosis of fever-induced type 1 ECG (F-type1) in a large BrS cohort.

Objectives: The objectives of this study were to assess the prognosis of F-type1 in asymptomatic BrS and to compare the effects of fever and drugs on ECG parameters.