Kir2.1 mutations differentially increase the risk of flecainide proarrhythmia in Andersen Tawil Syndrome.

Background: Flecainide and other class-Ic antiarrhythmic drugs (AADs) are widely used in Andersen-Tawil syndrome type 1 (ATS1) patients. However, class-Ic drugs might be proarrhythmic in some cases. We investigated the molecular mechanisms of class-I AADs proarrhythmia and whether they might increase the risk of death in ATS1 patients with structurally normal hearts.

Electrophysiological Phenotype-Genotype Study of Sustained Monomorphic Ventricular Tachycardia in Inherited, High Arrhythmic Risk, Left Ventricular Cardiomyopathy.

Background: Among inherited cardiomyopathies involving the left ventricle, whether dilated or not, certain genotypes carry a well-established arrhythmic risk, notably manifested as sustained monomorphic ventricular tachycardia (SMVT). Nonetheless, the precise localization and electrophysiological profile of this substrate remain undisclosed across different genotypes.

Methods: Patients diagnosed with cardiomyopathy and left ventricle involvement due to high-risk genetic variants and SMVT treated by electrophysiological study were recruited from 18 European/US centers.

Vector field heterogeneity as a novel omnipolar mapping metric for functional substrate characterization in scar-related ventricular tachycardias.

Background: Vector field heterogeneity (VFH) is a novel omnipolar metric to quantify local propagation heterogeneities that may identify functionally critical sites for ablation in scar-related ventricular tachycardia (VT).

Objective: This study aims to assess the diagnostic value of VFH to identify abnormal propagation patterns during ventricular substrate mapping and compare VFH in VT isthmus sites (IS), low-voltage bystander area (LVA) , and normal voltage areas (NVAa).

Methods: Substrate maps acquired with a 16-pole grid catheter in patients with scar-related VT were segmented into sites corresponding to IS, LVA, and NVA (defined as omnipolar voltages > and <1.

A rare presentation of infective endocarditis: Phase 4 block of the left bundle branch as key for the diagnosis. A case report.

Definitive diagnosis of infective endocarditis (IE) is mainly based on microbiological and imaging criteria. In a minority of cases, particularly when perivalvular area is involved, cardiac conduction disorders (CCD) may appear, which implies worse prognosis. In this scenario, different degrees of auriculoventricular block can occur, but development of bundle branch block is rare.

Phenotype and Clinical Outcomes in Desmin-Related Arrhythmogenic Cardiomyopathy.

Background: Desmin (DES) pathogenic variants cause a small proportion of arrhythmogenic cardiomyopathy (ACM). Outcomes data on DES-related ACM are scarce.

Objectives: This study sought to provide information on the clinical phenotype and outcomes of patients with ACM caused by pathogenic variants of the DES gene in a multicenter cohort.

Penetrance of Dilated Cardiomyopathy in Genotype-Positive Relatives.

Background: Disease penetrance in genotype-positive (G+) relatives of families with dilated cardiomyopathy (DCM) and the characteristics associated with DCM onset in these individuals are unknown.

Objectives: This study sought to determine the penetrance of new DCM diagnosis in G+ relatives and to identify factors associated with DCM development.

Methods: The authors evaluated 779 G+ patients (age 35.

Extracellular Kir2.1 Mutant Upsets Kir2.1-PIP Bonds and Is Arrhythmogenic in Andersen-Tawil Syndrome.

Background: Andersen-Tawil syndrome type 1 is a rare heritable disease caused by mutations in the gene coding the strong inwardly rectifying K channel Kir2.1. The extracellular Cys (cysteine)-to-Cys disulfide bond in the channel structure is crucial for proper folding but has not been associated with correct channel function at the membrane.

A gain-of-function HCN4 mutant in the HCN domain is responsible for inappropriate sinus tachycardia in a Spanish family.

In a family with inappropriate sinus tachycardia (IST), we identified a mutation (p.V240M) of the hyperpolarization-activated cyclic nucleotide-gated type 4 (HCN4) channel, which contributes to the pacemaker current (I) in human sinoatrial node cells. Here, we clinically study fifteen family members and functionally analyze the p.

Proposed diagnostic criteria for arrhythmogenic cardiomyopathy: European Task Force consensus report.

Arrhythmogenic cardiomyopathy (ACM) is a heart muscle disease characterized by prominent "non-ischemic" myocardial scarring predisposing to ventricular electrical instability. Diagnostic criteria for the original phenotype, arrhythmogenic right ventricular cardiomyopathy (ARVC), were first proposed in 1994 and revised in 2010 by an international Task Force (TF). A 2019 International Expert report appraised these previous criteria, finding good accuracy for diagnosis of ARVC but a lack of sensitivity for identification of the expanding phenotypic disease spectrum, which includes left-sided variants, i.

Emery-Dreifuss muscular dystrophy Type 1 is associated with a high risk of malignant ventricular arrhythmias and end-stage heart failure.

Background And Aims: Emery-Dreifuss muscular dystrophy (EDMD) is caused by variants in EMD (EDMD1) and LMNA (EDMD2). Cardiac conduction defects and atrial arrhythmia are common to both, but LMNA variants also cause end-stage heart failure (ESHF) and malignant ventricular arrhythmia (MVA). This study aimed to better characterize the cardiac complications of EMD variants.

Late gadolinium enhancement distribution patterns in non-ischaemic dilated cardiomyopathy: genotype-phenotype correlation.

Aims: Late gadolinium enhancement (LGE) is frequently found in patients with dilated cardiomyopathy (DCM); there is little information about its frequency and distribution pattern according to the underlying genetic substrate. We sought to describe LGE patterns according to genotypes and to analyse the risk of major ventricular arrhythmias (MVA) according to patterns.

Methods And Results: Cardiac magnetic resonance findings and LGE distribution according to genetics were performed in a cohort of 600 DCM patients followed at 20 Spanish centres.

Extracellular cysteine disulfide bond break at Cys122 disrupts PIP-dependent Kir2.1 channel function and leads to arrhythmias in Andersen-Tawil Syndrome.

Background: Andersen-Tawil Syndrome Type 1 (ATS1) is a rare heritable disease caused by mutations in the strong inwardly rectifying K channel Kir2.1. The extracellular Cys122-to-Cys154 disulfide bond in the Kir2.

Lifestyle physical activity and rapid-rate non-sustained ventricular tachycardia in arrhythmogenic cardiomyopathy.

Objective: To investigate the association of accelerometer-measured lifestyle physical activity with rapid-rate non-sustained ventricular tachycardias (RR-NSVTs) in patients with arrhythmogenic cardiomyopathy (AC).

Methods: This multicentre, observational study enrolled 72 patients with AC, including right, left and biventricular forms of the disease, with underlying desmosomal and non-desmosomal mutations. Lifestyle physical activity, objectively monitored with accelerometers (ie, movement sensors) and RR-NSVT, identified as >188 bpm and >18 beats from a textile Holter ECG for 30 days.

ROD2 domain filamin C missense mutations exhibit a distinctive cardiac phenotype with restrictive/hypertrophic cardiomyopathy and saw-tooth myocardium.

Introduction And Objectives: Missense mutations in the filamin C (FLNC) gene have been reported as cause of inherited cardiomyopathy. Knowledge of the pathogenicity and genotype-phenotype correlation remains scarce. Our aim was to describe a distinctive cardiac phenotype related to rare missense FLNC variants in the ROD2 domain.

Prevalence of bleeding secondary to anticoagulation and mortality in patients with atrial fibrillation admitted with SARS-CoV-2 infection.

Introduction And Purpose: Atrial fibrillation (AF) is common in patients admitted with severe COVID-19. However, there is limited data about the management of chronic anticoagulation therapy in these patients. We assessed the anticoagulation and incidence of major cardiovascular events in hospitalized patients with AF and COVID-19.

Searching for genetic modulators of the phenotypic heterogeneity in Brugada syndrome.

In Brugada syndrome, even within the same family where all affected individuals share the same mutation, phenotypic variation is prominent, with variable penetrance and expressivity, presenting different degrees of involvement. It is difficult to establish a direct correlation between genotype and phenotype to predict prognosis in complications and risk of sudden death. The factors that modulate this inter- and intra-familial phenotypic variability remain to be determined.

Ablation with zero-fluoroscopy of premature ventricular complexes from aortic sinus cusps: A single-center experience.

Background: Catheter ablation of premature ventricular complexes from aortic sinus cusps (ASC-PVC) is a complex procedure that conventionally requires coronary catheterization (CC) to localize coronary artery ostium (CAO). Little published information is available on the mapping and ablation with zero-fluoroscopy (ZF) of ASC-PVC. The aim of the study was to determine the efficacy and safety of ASC-PVC ablation with a ZF approach guided by 3D intracardiac echocardiography integration in the electroanatomical mapping system (ICE 3D-EAM).

Layer-Specific Global Longitudinal Strain Predicts Arrhythmic Risk in Arrhythmogenic Cardiomyopathy.

Arrhythmogenic cardiomyopathy (AC) is a life-threatening disease which predispose to malignant arrhythmias and sudden cardiac death (SCD) in the early stages of the disease. Risk stratification relies on the electrical, genetic, and imaging data. Our study aimed to investigate how myocardial deformation parameters may identify the subjects at risk of known predictors of major ventricular arrhythmias.

Characterization of hereditary transthyretin cardiac amyloidosis in Spain.

Introduction And Objectives: Hereditary transthyretin amyloidosis (hATTR) is a disease caused by mutations in the transthyretin gene that frequently shows cardiac involvement due to amyloid deposition in the myocardium. Our objective was to identify cardiac involvement in a Spanish cohort.

Methods: Retrospective multicenter study of patients diagnosed with hATTR with cardiac involvement from Spanish centers.