Search Results (87)

Arrhythmogenic cardiomyopathy (ACM) is a cardiac disorder manifesting through electrical and contractile dysfunction of the ventricles, characterized by fibro-fatty substitution of the myocardium. Cardiac mesenchymal stromal cells (CMSCs) are key contributors to this remodeling. In clinical management, several pharmacological approaches address ACM arrhythmias and heart failure, but, to date, none specifically target fibro-adipose replacement. Despite genetic origin, several studies have reported that non-genetic aspects influence ACM phenotype, including epigenetic factors. Little is known about their mechanisms in ACM and their potential therapeutic applications. In this work, we aimed to test whether, by perturbing the epigenetic landscape of ACM CMSCs, we could influence their propensity to fibro-fatty differentiation. We conducted a hypothesis-free screening of 157 epigenetic drugs on CMSCs, isolated from ACM patients. Through fluorescence assays, we evaluated lipid droplet accumulation, collagen deposition, and cell viability. Of the 157 drugs screened, five (splitomicin, suberohydroxamic acid, CPTH6, BVT-948, and PBIT) attenuated adipogenic differentiation of ACM CMSCs, with BVT-948 and CPTH6 also reducing collagen production. Overall, this study identified specific epigenetic drugs that were effective in reducing the fibro-fatty phenotype of ACM stromal cells, thus offering potential for adjunctive therapies in the clinical management of ACM patients. Full article

Arrhythmogenic cardiomyopathy (ACM) is a genetic cardiac disease characterized by a progressive loss of cardiomyocytes associated with fibrofatty myocardial replacement, resulting in a heightened risk of ventricular arrhythmias and sudden cardiac death. ACM is a common cause of sudden death in young individuals, and exercise has been proven to be a factor in disease progression. Current therapeutic strategies, including lifestyle modification, antiarrhythmic pharmacological therapy, catheter ablation, and the placement of implantable cardioverter-defibrillators, remain primarily palliative options rather than addressing the underlying molecular substrate. The pathogenesis of ACM includes complex molecular and cellular mechanisms, linking genetic mutations to structural and electrical anomalies of the ventricle. The lack of targeted therapies contributes to a challenging approach to the disease. It highlights the need for a better understanding of the mechanisms that lead to myocardial remodeling and arrhythmic predisposition. With the help of animal models (especially murine) and induced pluripotent stem cells, there have been advances in understanding the molecular pathogenesis of ACM. In this review, we summarized some of the pathogenic molecular pathways involved in the development of ACM and emerging therapies targeted towards disease modification, not just prevention. Full article

Arrhythmogenic cardiomyopathy (ACM; MIM #107970) is a primitive heart muscle disease characterized by progressive myocardial loss and fibrosis or fibrofatty replacement, predisposing patients to ventricular arrhythmias, sudden cardiac death, and heart failure. Despite advances in imaging and genetics, early diagnosis remains challenging due to incomplete penetrance, variable phenotypic expressivity, and the fact that fatal arrhythmic events may often occur in the early stages of the disease. In this context, the identification of reliable biomarkers could enhance diagnostic accuracy, support risk stratification, and guide clinical management. This narrative review examines the current landscape of potential and emerging biomarkers in ACM, including troponins, natriuretic peptides, inflammatory proteins, microRNAs, fibrosis-related markers, and other molecules. Several of these biomarkers have demonstrated associations with disease severity, arrhythmic burden, or structural progression, although their routine clinical utility remains limited. The increasing relevance of genetic testing and non-invasive tissue characterization—particularly through cardiac imaging techniques—should also be emphasized as part of a multimodal diagnostic strategy in which biomarkers may play a complementary role. Although no single biomarker currently meets the criteria for a standalone diagnostic application, ongoing research into multi-marker panels and novel molecular targets offers promising perspectives. In conclusion, the integration of circulating biomarkers with imaging findings, genetic data, and clinical parameters may open new avenues for improving early detection and supporting personalized therapeutic strategies in patients with suspected ACM. Full article

Background: Arrhythmogenic cardiomyopathy (ACM) is an inherited heart disorder characterized by structural and functional myocardial alterations, often accompanied by ventricular arrhythmias (VAs), which may ultimately result in sudden cardiac death (SCD). While mutations in genes coding for desmosomal components are commonly identified in affected individuals, genetic variants involving non-desmosomal proteins have recently been recognized as contributors to the disease’s etiology. In 2008, a mutation in the transmembrane protein 43 (TMEM43) was identified as being responsible for a fully penetrant, sex-related, and severe form of ACM. This review aimed to systematically synthesize the current evidence on the natural history, electrocardiographic, and imaging findings as well as the clinical outcomes of TMEM43 cardiomyopathy. Methods: A systematic search was performed in the PubMed, Scopus, and Web of Science databases, following the PRISMA guidelines, using the terms “TMEM43” AND “cardiomyopathy”. After an initial screening of 144 retrieved articles, 80 were considered relevant. Upon a full-text review and eligibility assessment, 12 studies involving 903 individuals harboring TMEM43 variants were selected for inclusion. Results: Male patients more frequently carried the pathogenic TMEM43 variant (n = 505, 55.9%) and exhibited an earlier arrhythmic onset of the disease (33.2 years old versus 46.2 years old in female patients), supporting the need for earlier implantable cardioverter–defibrillator implantation (30.4 versus 42.2 years old). Palpitations, chest pain, and syncope were the most common presenting symptoms. Baseline electrocardiograms commonly demonstrated poor R wave progression, QRS prolongation, and premature ventricular contractions (PVCs). Arrhythmic events, including malignant VAs and SCD, were early manifestations of the disease, especially in male patients. Frequent PVCs and left ventricular dilation were considered early markers of the disease and were predictive of arrhythmic events. Conversely, heart failure was reported as a late clinical outcome, requiring heart transplantation in a minority of cases (1.5%). Conclusions:TMEM43 cardiomyopathy is a fully penetrant autosomal dominant form of ACM, characterized by a well-defined clinical phenotype that is more severe and presents earlier in male patients. Full article

Arrhythmogenic cardiomyopathies (ACMs) are a phenotypically and etiologically heterogeneous group of myocardial disorders characterized by fibrotic or fibro-fatty replacement of ventricular myocardium, electrical instability, and an elevated risk of sudden cardiac death. Initially identified as a right ventricular disease, ACMs are now recognized to include biventricular and left-dominant forms. Genetic causes account for a substantial proportion of cases and include desmosomal variants, non-desmosomal variants, and familial gene-elusive forms with no identifiable pathogenic mutation. Nongenetic etiologies, including post-inflammatory, autoimmune, and infiltrative mechanisms, may mimic the phenotype. In many patients, the disease remains idiopathic despite comprehensive evaluation. Cardiac magnetic resonance imaging has emerged as a key tool for identifying non-ischemic scar patterns and for distinguishing arrhythmogenic phenotypes from other cardiomyopathies. Emerging classifications propose the unifying concept of scarring cardiomyopathies based on shared structural substrates, although global consensus is evolving. Risk stratification remains challenging, particularly in patients without overt systolic dysfunction or identifiable genetic markers. Advances in tissue phenotyping, multi-omics, and artificial intelligence hold promise for improved prognostic assessment and individualized therapy. Full article

Cardiac magnetic resonance imaging (CMRI) has become an indispensable tool in evaluating arrhythmic risk and guiding therapeutic decisions in patients with non-ischemic cardiomyopathies (NICMs), including dilated (DCM), hypertrophic (HCM), and arrhythmogenic cardiomyopathies (ACM). Both European and American guidelines have given an additive and different value of late gadolinium enhancement (LGE) in specific morpho-functional (hypertrophic, dilated, and arrhythmogenic) phenotypes. In particular, LGE plays a different weight in relation to different cardiomyopathies. In dilated cardiomyopathy, LGE is able to predict arrhythmic risk in relationship to the presence and localization (septal and/or ring like LGE). On the contrary, in HCM, LGE is related to increased risk of cardiac death according to the extent (LGE >15%), while in ACM, it has a greater role in the presence of fat infiltration associated with LGE. In this review, we aim to identify predictors of sudden cardiac death related to myocardial structural features seen in CMRI in cardiomyopathies, going beyond the sole assessment of left ventricular function and ejection fraction. Full article

Sudden cardiac death represents an unexpected death for which a strong underlying genetic background has been described. The primary causes are identified in cardiomyopathies and channelopathies, which are heart diseases of the muscle and electrical system, respectively, without coronary artery disease, hypertension, valvular disease, and congenital heart malformations. Genetic variants, especially single nucleotide variants and short insertions/deletions impacting essential myocardial functions, have shown that cardiomyopathies display high heritability. However, genetic heterogeneity, incomplete penetrance, and variable expression may complicate the interpretation of genetic findings, thus delaying the management of seriously at-risk patients. Moreover, recent studies show that the diagnostic yield related to genetic cardiomyopathies ranges from 28 to 40%, raising the need for further research. In this regard, investigating the occurrence of structural variants, especially copy number variants, may be crucial. Based on these considerations, this review aims to provide an overview of copy number variants identified in cardiomyopathies and discuss them, considering diagnostic yield. This review will ultimately address the necessity of incorporating copy number variants into routine genetic testing for cardiomyopathies and channelopathies, a process increasingly enabled by advances in next-generation sequencing technologies. Full article

Background/Objectives: PKP2 (MIM *602861) is the most commonly gene associated with Arrhythmogenic Cardiomyopathy (ACM), an inherited cardiac muscle disorder. The aim of this study was to characterize the phenotypical effect of a heterozygous pathogenic c.2443_2448delAACACCinsGAAA variant in PKP2 gene (NM_004572), detected in two Italian families. Methods: Next Generation Sequencing (NGS) analysis was carried out on two probands, testing a multigenic targeted panel. Segregation analysis through Sanger sequencing detected other three and six positive members, in Family 1 and 2, respectively. Thus, eleven positive patients were identified overall. A deep clinical evaluation was performed according to age groups and clinical parameters (symptoms, electrocardiogram, imaging, and devices). To investigate the molecular effect of the identified variant on PKP2 expression level, total RNA was isolated from peripheral blood mononuclear cells (PBMCs) and quantitative RT-polymerase chain reaction was performed. PKP2 expression at the protein level was analyzed on PBMCs by Western blot analysis. Results: PKP2 transcriptional levels resulted to be reduced by 48% in cells carrying c.2443_2448delAACACCinsGAAA variant compared to WT cells (p = 0.00015). Importantly, Western blot confirmed the reduced level of PKP2 protein in two heterozygous carriers of the variant, confirming the haploinsufficiency effect. Conclusions: The clinical onset of ACM can be Sudden Cardiac Death, and hence, it is recommended to perform a segregation test on first-degree relatives of pathogenic variant carriers, even if they are asymptomatic, with the purpose of promptly detecting those at risk. Full article

Arrhythmogenic cardiomyopathy (ACM) is an inherited heart disease characterized by fibrofatty replacement of the ventricular myocardium, with an estimated prevalence of 1:5000 people in the general population. Sudden cardiac death is the first manifestation of this disease in 16–23% of patients with ACM. Fibrofatty infiltration can be identified with noninvasive cardiac magnetic resonance. Studies of epicardial fat deposits have suggested pathogenic roles of epicardial fats in mediating cardiac diseases and arrhythmias. Although myocardial fat infiltration has been well described in ACM, changes in epicardial fat deposits with this disease have not been well investigated. Our study shows that patients with ACM have a higher amount of EAT compared to controls. Additionally, the EAT amount seems to increase with the evolution of the disease. Full article

Inherited arrhythmia syndromes include several different diseases, as well as Brugada syndrome (BrS), long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), and short QT syndrome (SQTS). They represent, together with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C), an important cause of sudden cardiac death in the young. Most arrhythmia syndromes are inherited in an autosomal dominant manner, and genetic studies are suggested.: to report the spectrum of genetic variations and clinical phenotype in an Italian cohort with confirmed inherited arrhythmia syndromes and arrhythmogenic cardiomyopathy using whole-exome sequencing (WES). Patients with confirmed inherited arrhythmia syndromes and hereditary cardiomyopathy were recruited at the Cardiology Unit, University Polyclinic Hospital of Foggia, Italy and were included in this study. Genomic DNA samples were extracted from peripheral blood and conducted for WES. The variants were annotated using BaseSpace Variant Interpreter Annotation Engine 3.15.0.0 (Illumina). Reported variants were investigated using ClinVar, VarSome Franklin and a literature review. They were categorised agreeing to the criteria of the American College of Medical Genetics and Genomics. Overall, 62 patients were enrolled. Most of them had a clinical diagnosis of BrS (n 48, 77%). The remaining patients included in the present study had diagnosis of confirmed LQT (n 7, 11%), AR-DCM (n 4, 6.5%), ARVD (n 2, 3%), and SQT (n 1, 1.6%). Using the WES technique, 22 variants in 15 genes associated with Brugada syndrome were identified in 21 patients (34%). Among these, the SCN5A gene had the highest number of variants (6 variants, 27%), followed by KCNJ5 and CASQ2 (2 variants). Only one variant was identified in the remaining genes. In 27 patients with a clinical diagnosis of BrS, no gene variant was detected. In patients with confirmed LQT, SQT, 10 variants in 9 genes were identified. Among patients with ARVD and AR-DCM, 6 variants in 5 genes were found. Variants found in our cohort were classified as pathogenic (6), likely pathogenic (3), of uncertain significance (26), and benign (1). Two additional gene variants were classified as risk factors. In this study, 13 novel genetic variations were recognized to be associated with inherited arrhythmogenic cardiomyopathies. Our understanding of inherited arrhythmia syndromes continues to progress. The era of next-generation sequencing has advanced quickly, given new genetic evidence including pathogenicity, background genetic noise, and increased discovery of variants of uncertain significance. Although NGS study has some limits in finding the full genetic data of probands, large-scale gene sequencing can promptly be applied in real clinical practices, especially in inherited and possibly fatal arrhythmia syndromes. Full article

Background and Objectives: The pathophysiology of arrhythmogenic cardiomyopathy (ACM), previously known as arrhythmogenic right ventricular cardiomyopathy (ARVC), and its specific biological features remain poorly understood. High-throughput plasma proteomic profiling, a powerful tool for gaining insights into disease pathophysiology at the systems biology level, has not been used to study ACM. This study aimed at characterizing plasmatic protein changes in patients with ACM, which were compared with those of healthy controls, and at exploring the potential role of the identified proteins as biomarkers for diagnosis and monitoring. Materials and Methods: Blood samples were collected from six ACM patients, four patients with other cardiomyopathies, and two healthy controls. Plasma was processed to remove high-abundance proteins and analyzed by two-dimensional gel electrophoresis. Differential protein expressions were assessed using PDQuest software, Bio-Rad US version 8.0.1. Results: The analysis revealed several proteins with altered expressions between ACM patients and controls, including plakophilin-2, junctional plakoglobin, desmoplakin, desmin, transmembrane protein 43, and lamin A/C. Conclusions: The plasma proteomic profiling of ACM suggests that ACM is a distinct disease entity characterized by a unique dysregulation of desmosomal proteins. The identification of plasma biomarkers associated with ACM underscores their potential to improve diagnostic accuracy and facilitate early intervention strategies. Further exploration of mutations in desmosomal proteins and their phosphorylation states may provide deeper insights into the pathophysiology of ACM. Full article

Background: Arrhythmogenic cardiomyopathy (ACM) is a genetic disorder characterized by fibrofatty replacement of myocardial tissue, predominantly affecting the right ventricle (RV), but often involving the left ventricle (LV) as well. The early detection of fibrosis, crucial for risk stratification, has been enhanced by advanced imaging techniques. Global longitudinal strain (GLS) has shown promise as a surrogate marker for late enhancement (LE) in identifying myocardial fibrosis, yet precise cut-off values for strain are lacking. The aim of the study is to evaluate LV strain as a predictor of LE in ACM and to define strain cut-offs for early fibrosis detection, enhancing non-invasive diagnostic accuracy. Methods: This retrospective single-center study included 64 patients diagnosed with ACM. Echocardiographic analysis using speckle-tracking echocardiography was performed to assess LV strain. LE was evaluated through cardiac magnetic resonance (CMR) or via cardiac computed tomography (CCT) in cases with CMR contraindications. The study aimed to correlate regional LV strain values with the presence of LE, identifying cut-off values predictive of fibrosis. Results: The study found significant correlations between reduced LV strain values and the presence of LE, particularly in the anterolateral and inferolateral segments (p < 0.05). Specific strain thresholds, such as those for segment 12 (p = 0.02) and segment 17 (p = 0.03), were identified as predictive markers for LE. These findings suggest that strain imaging could serve as a non-invasive tool for the early detection of myocardial fibrosis in ACM patients. Conclusions: LV strain analysis offers potential as a non-invasive surrogate marker for myocardial fibrosis in ACM. Incorporating strain imaging into routine echocardiographic evaluations could improve early diagnosis and risk stratification, guiding patient management. Full article

Background: Arrhythmogenic cardiomyopathy (ACM) is a genetic disorder responsible for nearly a quarter of sports-related sudden cardiac deaths. ACM cases caused by mutations in desmosome proteins lead to right ventricular enlargement, the loss of cardiomyocytes, and fibrofatty tissue replacement, disrupting electrical and mechanical stability. It is currently unknown how paracrine factors secreted by infiltrating fatty tissues affect ACM cardiomyocyte electrophysiology. Methods: A normal and a PKP2 mutant (c.971_972InsT) ACM hiPSC line were cultivated and differentiated into cardiomyocytes (CMs). Adipocytes were differentiated from human adipose stem cells, and adipocyte conditioned medium (AdCM) was collected. Optical mapping and phenotypic analyses were conducted on human iPSC-cardiomyocytes (hiPSC-CMs) cultured in cardiac maintenance medium (CMM) and either with AdCM or specific cytokines. Results: Significant differences were observed in voltage parameters such as the action potential duration (APD₈₀, APD₃₀), conduction velocity (CV), and CV heterogeneity. When cultured in AdCM relative to CMM, the APD₈₀ increased and the CV decreased significantly in both groups; however, the magnitudes of changes often differed significantly between 1 and 7 days of cultivation. Cytokine exposure (IL-6, IL-8, MCP-1, CFD) affected the APD and CV in both the normal and PKP2 mutant hiPSC-CMs, with opposite effects. NF-kB signaling was also found to differ between the normal and PKP2 mutant hiPSC-CMs in response to AdCM and IL-6. Conclusions: Our study shows that hiPSC-CMs from normal and mPKP2 ACM lines exhibit distinct molecular and functional responses to paracrine factors, with differences in RNA expression and electrophysiology. These different responses to paracrine factors may contribute to arrhythmogenic propensity. Full article

Athlete’s heart (AH) represents the heart’s remarkable ability to adapt structurally and functionally to prolonged and intensive athletic training. Characterized by increased left ventricular (LV) wall thickness, enlarged cardiac chambers, and augmented cardiac mass, AH typically maintains or enhances systolic and diastolic functions. Despite the positive health implications, these adaptations can obscure the difference between benign physiological changes and early manifestations of cardiac pathologies such as dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), and arrhythmogenic cardiomyopathy (ACM). This article reviews the imaging characteristics of AH across various modalities, emphasizing echocardiography, cardiac magnetic resonance (CMR), and cardiac computed tomography as primary tools for evaluating cardiac function and distinguishing physiological adaptations from pathological conditions. The findings highlight the need for precise diagnostic criteria and advanced imaging techniques to ensure accurate differentiation, preventing misdiagnosis and its associated risks, such as sudden cardiac death (SCD). Understanding these adaptations and employing the appropriate imaging methods are crucial for athletes’ effective management and health optimization. Full article