Diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia: proposed modification of the Task Force Criteria

[Guideline update: phenotype-based management of cardiomyopathy]

The 2023 ESC Cardiomyopathy Guidelines offer a comprehensive framework for diagnosing and managing cardiomyopathies. Building on a nuanced classification system, the guidelines introduce phenotypic descriptions that integrate genetic and non-genetic etiologies. Notably, the guidelines redefine cardiomyopathies, such as non-dilated left ventricular cardiomyopathy, emphasizing detailed myocardial tissue characterization and advanced imaging techniques like cardiac magnetic resonance to enhance diagnosis and treatment. Additionally, the role of genetic testing is highlighted, including family screening and personalized risk stratification for sudden cardiac death prevention. The guidelines stress a patient-centered, multidisciplinary approach, ensuring individualized care across all life stages, from pediatric to adult care. Key updates include new therapeutic options, such as myosin inhibitors for hypertrophic cardiomyopathy. The guidelines also underscore the importance of distinguishing transient syndromes, such as Takotsubo syndrome, from chronic cardiomyopathies, recommending careful assessment of arrhythmias and phenotypic traits to avoid misclassification. This refined approach aims to optimize clinical outcomes through accurate diagnosis, genetic evaluation, and a focus on lifelong management.

Utility of MRI and CT in Sports Cardiology

Sports cardiologists specialize in the care of competitive athletes and highly active people by detecting and managing cardiovascular diseases that can impact sports participation and counseling on return to sports after cardiovascular events. Preparticipation evaluation of athletes includes history, physical examination, and electrocardiography (ECG), with exercise ECG added when screening master athletes. If the findings are abnormal or inconclusive, echocardiography is used for further evaluation. Further imaging with MRI, CT, or stress test is performed for establishing a diagnosis when echocardiography is indeterminate or discordant with clinical features and for risk stratification if echocardiography provides a definitive diagnosis. MRI can help distinguish athlete's heart from similar-appearing pathologic entities when echocardiography is inconclusive. Athlete's heart can manifest as left ventricular hypertrophy (LVH), left ventricle (LV) dilatation, prominent LV trabeculations, and right ventricular (RV) dilatation. Adaptive LVH in athletes is concentric and typically measures less than 16 mm, which distinguishes it from pathologic LV thickening of hypertrophic cardiomyopathy, hypertension, valvular disease, and infiltrative cardiomyopathies. Adaptive LV dilatation with normal or mildly reduced ejection fraction can be seen in endurance athletes. LV ejection fraction greater than 40%, augmentation of LV ejection fraction with exercise, and normal or supranormal diastolic function distinguishes it from dilated cardiomyopathy. Physiologic RV dilatation in athletes is distinguished from arrhythmogenic cardiomyopathy (RV type) by global involvement and absence of major regional wall motion abnormalities or late gadolinium enhancement. MRI is also useful in diagnosis and risk stratification of athletes with cardiovascular symptoms and after major cardiovascular events such as arrhythmias, myocardial infarction, and resuscitated sudden cardiac death or arrest. CT angiography provides accurate evaluation of coronary artery anomalies and coronary artery disease. ©RSNA, 2025 Supplemental material is available for this article.

Imaging Features of Desmoplakin Arrhythmogenic Cardiomyopathy: A Comparative Cardiac Magnetic Resonance Study

BACKGROUND

Arrhythmogenic cardiomyopathy (ACM) related to Desmoplakin (DSP) mutations is a distinct condition associated with particularly severe outcomes, more frequent left ventricular (LV) involvement including fibrosis, dysfunction and inflammatory episodes. Whether DSP-ACM is associated with specific imaging features remains elusive.

PURPOSE

To provide a comprehensive description of cardiac magnetic resonance (CMR) findings in patients with DSP-ACM and to compare them to RV-dominant ACM with LV involvement (LV+ right-dominant-ACM).

METHODS

Patients with DSP-ACM matched with patients with ACM related toa non-DSP desmosomal mutation and ≥1 feature of LV involvement underwent CMR in two institutions. Biventricular metrics and segmental wall motion abnormalities (WMA) were assessed. LV late gadolinium enhancement (LGE) was assessed both qualitatively and quantitatively after semi-automated segmentation.

RESULTS

Overall, 70 ACM patients were analyzed; 37 with DSP-ACM and 33 in the LV+ right-dominant-ACM group. LVEF was significantly lower in the DSP-ACM group (46±12%) than in the LV+ right-dominant-ACM group (56±10%, P=0.001). Conversely, RVEF was significantly higher in the DSP-ACM group (45±11% vs. 40±12%, P=0.04) and both RV end-diastolic (100±24 vs 130±44mL/m², P=0.002) and end-systolic (56±21 vs 81±45mL/m², P=0.007) indexed volumes were significantly smaller in DSP-ACM as compared to the LV+ right-dominant-ACM group. The LV to RV end-systolic volume ratio (0.96[IQR0.70-1.27] vs. 0.59[IQR0.48-0.69]) was significantly higher in the DSP-ACM group (P<0.0001), and had a good performance in differentiating both groups (area under the ROC curve 0.86, optimal threshold 0.8). Patients in the DSP-ACM group had significantly more LV and less RV WMA than those in the LV+ right-dominant-ACM group. The amount of LGE was significantly higher in the DSP group (14±16 vs. 2±3%, P<0.0001) and present in the majority of LV segments, particularly in the lateral and inferior walls, as compared to LV+ right-dominant-ACM patients. Transmural LGE and the presence of a ring-like pattern corresponding to circumferential subepicardial LGE involving ≥3contiguous LV basal segments were highly suggestive of DSP-ACM.

CONCLUSIONS

The presence of LV to RV end-systolic volume ratio>0.8, global LGE>5%, transmural and/or a ring-like LGE pattern are highly suggestive of DSP-ACM and should prompt careful diagnostic assessment considering the severe associated outcomes.

2025 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2025 AHA Statistical Update is the product of a full year's worth of effort in 2024 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. This year's edition includes a continued focus on health equity across several key domains and enhanced global data that reflect improved methods and incorporation of ≈3000 new data sources since last year's Statistical Update.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Arrhythmogenic Right Ventricular Cardiomyopathy: A Comprehensive Review

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by structural abnormalities, arrhythmias, and a spectrum of genetic and clinical manifestations. Clinically, ARVC is structurally distinguished by right ventricular dilation due to increased adiposity and fibrosis in the ventricular walls, and it manifests as cardiac arrhythmias ranging from non-sustained ventricular tachycardia to sudden cardiac death. Its prevalence has been estimated to range from 1 in every 1000 to 5000 people, with its large range being attributed to the variability in genetic penetrance from asymptomatic to significant burden. It is even suggested that the prevalence is underestimated, as the presence of genotypic mutations does not always lead to clinical manifestations that would facilitate diagnosis. Additionally, while set criteria have been in place since the 1990s, newer understanding of this condition and advancements in cardiac technology have prompted multiple revisions in the diagnostic criteria for ARVC. Novel discoveries of gene variants predisposing patients to ARVC have led to established screening techniques while providing insight into genetic counseling and management. This review aims to provide an overview of the genetics, pathophysiology, and clinical approach to ARVC. It will also focus on clinical presentation, ARVC diagnostic criteria, electrophysiological findings, including electrocardiogram characteristics, and imaging findings from cardiac MRI, 2D, and 3D echocardiogram. Current management options-including anti-arrhythmic medications, device indications, and ablation techniques-and the effectiveness of treatment will also be reviewed.

Impaired Atrial and Ventricular Strain Predicts Heart Failure in Arrhythmogenic Right Ventricular Cardiomyopathy

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy (ARVC) increases the risk of heart failure (HF) and arrhythmias. Speckle-tracking echocardiography (STE) detects myocardial dysfunction, but its predictive role for HF in this population remains unclear.

METHODS

Seventy-one patients with ARVC (age 43.7 ± 14.8 years, 53.5% male) without prevalent HF at baseline who were enrolled in the Johns Hopkins ARVC Registry were retrospectively included. Global strain (GS) and strain rate (SR) of the left ventricle (LV), right ventricle free wall (RVFW), left atrium (LA), and right atrium (RA) were measured by a blinded operator. Cox regression models assessed their association with incident HF.

RESULTS

Incident HF developed in 23 patients (age 49.3 ± 12.5 years, 52.2% male) during a median follow-up of 2.7 years. Decreases in strain were significantly associated with HF: LV peak global longitudinal systolic strain (GLS; hazard ratio [HR] 1.20, 95% confidence interval [CI] 1.06-1.35; P = 0.003), RVFW strain (HR 1.11, 95% CI 1.04-1.18; P = 0.003), LA GS (HR 1.05, 95% CI 1.00-1.09; P = 0.030), and RA GS (HR 1.07, 95% CI 1.03-1.12; P < 0.001). Associations for LV GLS, RVFW strain, and RA GS remained significant after adjusting for age and sex. Strain values frequently fell below established reference ranges. Any strain value (LV GLS, RVFW strain, LA GS, or RA GS) below the normal limit was associated with an 8-fold increase in HF (HR 8.43, 95% CI 1.97-36.02; P = 0.004), and each individual component below the normal threshold doubled the risk (HR 2.35, 95% CI 1.60-3.45; P < 0.001).

CONCLUSIONS

STE deformation abnormalities are associated with incident HF in ARVC patients. Echocardiographic strain may aid in identifying patients at risk of HF for closer follow-up and management.

Contemporary diagnostic approach to arrhythmogenic cardiomyopathy: The three-step work-up

Arrhythmogenic Cardiomyopathy (ACM) is a cardiac disorder characterized by non-ischemic myocardial scarring, which may lead to ventricular electrical instability and systolic dysfunction. Diagnosing ACM is challenging as there is no single gold-standard test and a combination of criteria is required. The first diagnostic criteria were established in 1994 and revised in 2010, focusing primarily on right ventricular involvement. However, in 2019, an international expert report identified limitations of previous diagnostic scoring and developed the 2020 Padua criteria with also included criteria for diagnosis of left ventricular variants and introduced cardiac magnetic resonance tissue characterization findings for detection of left ventricular myocardial scar. These criteria were further refined and published in 2023 as the European Task Force criteria, gaining international recognition. This review provides an overview of the 20 years of progresses on the disease diagnostic from the original 1994 criteria to the most recent 2023 European criteria, highlighting the evolution into our understanding of the pathobiology and morpho-functional features of the disease.

Coonar A, Gimeno JR, Lazaros G, Lerakis S, Mestroni L, Papadopoulos G, Pecchia L, Prandi FR, Syrris P, Cadrin-Turigny J, Vasilakis A, Saffitz JE, Gaetano Thiene S, Elliott PM, Kaski JP, McKenna WJ, Bossone E, Limongelli G, Tsatsopoulou A. Naxos Disease and Related Cardio-Cutaneous Syndromes

Naxos disease is a rare autosomal recessive condition combining arrhythmogenic right ventricular cardiomyopathy, woolly hair, and palmoplantar keratoderma. The first identified causative variant was in the gene encoding the desmosomal protein plakoglobin. Naxos disease exhibits fibro-fatty myocardial replacement with immunohistological abnormalities in cardiac protein and signaling pathways, highlighting the role of inflammation and potential anti-inflammatory treatments. Childhood cutaneous signs precede cardiac features, which are diagnosed by familial and genetic evaluation, electrocardiography and cardiac imaging. Disease progression necessitates holistic care with risk management and lifestyle adjustments, often needing treatment for arrhythmia and heart failure. Similar phenotypes have been linked to desmoplakin and rarely desmocollin2 gene variants, highlighting the importance of familial and genetic evaluation. This document summarizes current knowledge on Naxos disease and related cardiocutaneous syndromes and initiates an international endeavor to collect and study all global cases, aiming to improve understanding, treatment, and patient care through shared data and research.

Coexistence of cardiac sarcoidosis and arrhythmogenic cardiomyopathy-associated genetic variants: a multicentre case-control study

BACKGROUND

Cardiac sarcoidosis (CS) is a chronic inflammatory disease characterised by non-caseating granulomas, while arrhythmogenic cardiomyopathy (ACM) is a genetic condition mainly affecting desmosomal proteins. The coexistence of CS and genetic variants associated with ACM is not well understood, creating challenges in diagnosis and management. This study aimed to describe the clinical, imaging and genetic features of patients with both conditions.

METHODS

This was a multicentre retrospective case-control study involving three groups of patients: those with biopsy-proven CS and pathogenic or likely pathogenic genetic variants linked to ACM (n=5); patients with genetic variants but no CS (n=5); and patients with CS without genetic variants (n=5). Clinical data, including symptoms, electrocardiographic findings and imaging results from echocardiography, cardiac magnetic resonance and positron-emission tomography, were analysed.

RESULTS

Patients with CS and genetic variants were more likely to exhibit atrioventricular block (100%), PR prolongation (204 ms vs 160 ms) and paroxysmal atrial fibrillation (80%) compared with those with genetic variants alone (0% for both). Imaging findings showed a higher prevalence of septal involvement in patients with both conditions (80%) than in those with genetic variants alone (20%). No significant differences were observed between patients with CS and genetic variants and those with CS without genetic variants. The genetic variants identified included variants in PKP2 (40%), DSG2 (20%), DSP (20%) and TTN (20%).

CONCLUSIONS

The coexistence of CS and ACM-associated genetic variants is associated with distinct clinical features, including PR prolongation, AVB1°, septal involvement and paroxysmal atrial fibrillation. These findings emphasise the need to evaluate for CS in individuals with ACM and associated genetic variants who present with conduction abnormalities or septal involvement, guiding tailored diagnostic and therapeutic strategies.

Clinical features and outcomes in carriers of pathogenic desmoplakin variants

BACKGROUND AND AIMS

Pathogenic variants in the desmoplakin (DSP) gene are associated with the development of a distinct arrhythmogenic cardiomyopathy phenotype not fully captured by either dilated cardiomyopathy (DCM), non-dilated left ventricular cardiomyopathy (NDLVC), or arrhythmogenic right ventricular cardiomyopathy (ARVC). Prior studies have described baseline DSP cardiomyopathy genetic, inflammatory, and structural characteristics. However, cohort sizes have limited full clinical characterization and identification of clinical and demographic predictors of sustained ventricular arrhythmias (VAs), heart failure (HF) hospitalizations, and transplant/death. In particular, the relevance of acute myocarditis-like episodes for subsequent disease course is largely unknown.

METHODS

All patients with pathogenic/likely pathogenic (P/LP) DSP variants in the worldwide DSP-ERADOS Network (26 academic institutions across nine countries) were included. The primary outcomes were the development of sustained VA and HF hospitalizations during follow-up. Fine-Gray regressions were used to test association between clinical and instrumental parameters and the development of outcomes.

RESULTS

Eight hundred patients [40.3 ± 17.5 years, 47.5% probands, left ventricular ejection fraction (LVEF) 49.5 ± 13.9%] were included. Over 3.7 [1.4-7.1] years, 139 (17.4%, 3.9%/year) and 72 (9.0%, 1.8%/year) patients experienced sustained VA and HF episodes, respectively. A total of 32.5% of individuals did not fulfil diagnostic criteria for ARVC, DCM, or NDLVC; their VA incidence was 0.5%/year. In multivariable regression, risk features associated with the development of VA were female sex [adjusted hazard ratio (aHR) 1.547; P = .025], prior non-sustained ventricular tachycardia (aHR 1.721; P = .009), prior sustained VA (aHR 1.923; P = .006), and LVEF ≤ 50% (aHR: 1.645; P = .032), while for HF, they were the presence of T-wave inversion in 3+ electrocardiogram leads (aHR 2.036, P = .007) and LVEF ≤ 50% (aHR 3.879; P < .001). Additionally, 70 (8.8%) patients experienced a myocardial injury episode at presentation or during follow-up. These episodes were associated with an increased risk of VA and HF thereafter (HR 2.394; P < .001, and HR 5.064, P < .001, respectively).

CONCLUSIONS

Patients with P/LP DSP variants experience high rates of sustained VA and HF hospitalizations. These patients demonstrate a distinct clinical phenotype (DSP cardiomyopathy), whose most prominent risk features associated with adverse clinical outcomes are the presence of prior non-sustained ventricular tachycardia or sustained VA, T-wave inversion in 3+ leads on electrocardiogram, LVEF ≤ 50%, and myocardial injury events.

The role of genetic testing in management and prognosis of individuals with inherited cardiomyopathies

Inherited cardiomyopathies are a heterogeneous group of heart muscle conditions where disease classification has traditionally been based on clinical characteristics. However, this does not always align with genotype. While there are well described challenges of genetic testing, understanding the role of genotype in patient management is increasingly required. We take a gene-by-gene approach, reviewing current evidence for the role of genetic testing in guiding prognosis and management of individuals with inherited cardiomyopathies. In particular, focusing on causal variants in genes definitively associated with arrhythmogenic cardiomyopathy, dilated cardiomyopathy, and hypertrophic cardiomyopathy. This review identifies genotype-specific disease sub-groups with strong evidence supporting the use of genetics in clinical management and highlights that at present, the spectrum of clinical utility is not reflected in current guidelines. Of 13 guideline or expert consensus statements for management of cardiomyopathies, there are seven gene-specific therapeutic recommendations that have been published from four documents. Understanding how genotype influences phenotype provides evidence for the role of genetic testing for prognostic and therapeutic purposes, moving us closer to precision-medicine based care.

A right ventricular bulge: A clinical dilemma in diagnosis

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited disease characterized by progressive fibrofatty tissue replacement of the myocardium. Asymptomatic individuals can often present for the first time with acute cardiac symptoms, such as syncope and ventricular arrhythmias or sudden cardiac death (SCD), which can occur in young and athletic populations. In the field of inherited cardiomyopathies, ARVC is one of the most challenging to diagnose due to its variable expressivity, incomplete penetrance, and lack of specific, unique diagnostic criteria. Without additional clinical findings or context, current imaging modalities are unable to definitively distinguish ARVC from other disease entities. Right ventricular (RV) structural changes can lead to prominent ARVC features. An important component of the 2010 revised task force criteria (TFC) is the assessment of RV wall motion contraction by echocardiography; however, this can be difficult to assess. This case report explores the diagnostic criteria used for ARVC and the role of RV wall motion contraction in the diagnosis.

A new prediction model for sustained ventricular tachycardia in arrhythmogenic cardiomyopathy

Background

Arrhythmogenic cardiomyopathy (ACM) is an inherited cardiomyopathy characterized by high risks of sustained ventricular tachycardia (sVT) and sudden cardiac death. Identifying patients with high risk of sVT is crucial for the management of ACM.

Methods

A total of 147 ACM patients were retrospectively enrolled in the observational study and divided into training and validation groups. The least absolute shrinkage and selection operator (LASSO) regression model was employed to identify factors associated with sVT. Subsequently, a nomogram was constructed based on multivariable logistic regression analysis. The performance of the nomogram was evaluated using the area under the curve (AUC) of the receiver operating characteristic (ROC) curve and calibration curve. Decision curve analysis was conducted to assess the clinical utility of the nomogram.

Results

Seven parameters were incorporated into the nomogram: age, male sex, syncope, heart failure, T wave inversion in precordial leads, left ventricular ejection fraction (LVEF), SDNN level. The AUC of the nomogram to predict the probability of sVT was 0.867 (95% CI, 0.797-0.938) in the training group and 0.815 (95% CI, 0.673-0.958) in the validation group. The calibration curve demonstrated a good consistency between the actual clinical results and the predicted outcomes. Decision curve analysis indicated that the nomogram had higher overall net benefits in predicting sVT.

Conclusion

We have developed and internally validated a new prediction model for sVT in ACM. This model could serve as a valuable tool to accurately identify ACM patients with high risk of sVT.

Long-Term Outcomes in ICD: All-Causes Mortality and First Appropriate Intervention in Ischemic and Nonischemic Etiologies

Real-life data comparing the long-term outcome in patients with different heart diseases carrying an implantable cardioverter defibrillator (ICD) are scarce. This study aimed to compare the long-term risk of the first appropriate ICD intervention and overall survival in patients with ICD and heart disease of different etiologies. Patients with an ICD implanted between January 1, 2010, and December 31, 2022, followed in our center were included. Study outcomes were all-cause mortality and first appropriate ICD intervention. A comparison between ischemic heart disease (IHD) and non-IHD (NIHD) was performed. In NIHD different etiologies of dilated cardiomyopathy (DCM) were analyzed. Overall, 1184 patients (592 IDH; 592 NIHD) were included. During a median follow-up of 53 months all-cause death occurred in 399 patients (34%) whereas first appropriate ICD intervention occurred in 320 (27%). All-cause mortality was significantly higher in IHD vs NIHD patients (60% vs 43%; p <0.0001) but no differences in appropriate ICD intervention rate at 10 years (34% vs 40%; p = 0.125) were observed. In patients with NIHD, a higher 10-year mortality rate was found in valvular heart disease, post-radio/chemotherapy DCM (rctDCM), and hypertensive DCM. Hypertrophic cardiomyopathy, alcoholic DCM, and rctDCM were the least arrhythmic phenotypes in NIHD. Of note, inappropriate interventions in alcoholic DCM and rctDCM were higher than appropriate ones. In conclusion, the rate of ICD-appropriate interventions and mortality is different according to the etiology of heart disease and cardiovascular risk profile; this should be taken into consideration in the prognostic stratification of these patients at the time of implantation.

Strain Analysis for Early Detection of Fibrosis in Arrhythmogenic Cardiomyopathy: Insights from a Preliminary Study

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.

Prognostic Value of Circulating Biomarkers of Fibrotic Remodeling in Arrhythmogenic Cardiomyopathy

Arrhythmogenic cardiomyopathy (ACM) is a nonischemic, familial heart disease with a high risk of sudden cardiac death (SCD) in the pediatric population and accounts for >20% of SCDs worldwide [...].

Adipocyte-Mediated Electrophysiological Remodeling of PKP-2 Mutant Human Pluripotent Stem Cell-Derived Cardiomyocytes

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.

Concealed cardiomyopathy as an emerging cause of sudden cardiac arrest and sudden cardiac death

The inherited cardiomyopathies exhibit a broad spectrum of disease, with some patients remaining asymptomatic throughout life, while, for others, the first symptom of disease is sudden cardiac death at a young age. The risk of malignant ventricular arrhythmia in these conditions has traditionally been linked to the degree of structural myocardial abnormalities and functional impairment. However, recent advances in genetic testing and knowledge of the genetic basis of the diseases have led to the identification of concealed cardiomyopathy, in which sudden cardiac arrest or sudden cardiac death occurs in the absence of observable clinical features of cardiomyopathy, with a diagnosis being made only after the identification of a causative genetic variant. Increased awareness of concealed cardiomyopathy, a better understanding of mechanisms of arrhythmia and identification of risk modulators will be vital to improve care for families with concealed cardiomyopathy.

Morphological phenotype of right ventricular outflow tract is associated with cardiovascular outcomes and premature death

Morphology of right ventricular outflow tract (RVOT) is potentially related to cardiovascular outcomes. However, this relationship still remains to be verified with direct evidence. We retrospectively reviewed cases from the autopsy specimen library in the Center of Forensic Medicine in Sun Yat-sen University from 2017 to 2023. Six RVOT morphological characteristics were measured and their association with cardiovascular diseases (CVDs), sudden cardiac death (SCD) and age at death was evaluated. Relationship between myocardial fibrosis in RVOT and CVDs was investigated. RVOT characteristics were recruited by machine learning algorithms for diagnosing CVDs. A total of 2370 cases were finally recruited. Perimeter of sub-valve plane (pSBV) in RVOT was positively associated with risk of CVDs and SCD (OR: 1.21, 95%CI: 1.07-1.37, p = 0.003; OR: 1.33, 95%CI: 1.16-1.52, p < 0.001). Compared with thickness of septum (tS) < 3.0 mm, tS ≥ 3.0 mm was associated with premature death in disease-dominant death (β=-0.16, 95%CI: -0.20 to -0.11, p < 0.001) and SCD (β=-0.15, 95%CI: -0.21 to -0.10, p < 0.001). Degree of myocardial fibrosis in the posterior septum was increased in coronary atherosclerosis (6.86%±2.48% vs. 4.91%±2.14%, p = 0.011) and cardiomyopathies (8.11%±3.24% vs. 4.88%±3.11%, p = 0.005). A logistic regression model, recruiting age, left and right ventricular wall thickness, pSBV, circumference of pulmonary annulus and aortic annulus, was elected as an optimal diagnostic model of CVDs, yielding AUC of 0.734 (95%CI: 0.705-0.763), 0.781 (0.740-0.821) and 0.763 (0.725-0.800) in training, validation and test sets. Increased pSBV significantly correlates with higher risk of CVDs and SCD. And tS ≥ 3.0 mm is an independent risk factor of premature death regardless of diseases.

"Hot phase" clinical presentation of biventricular arrhythmogenic cardiomyopathy: when the perfect electrical storm spontaneously stops

An 18-year-old male presented with syncope during a training break. Post-syncope, he developed effort dyspnea, which he associated with the Pfizer-BioNTech COVID-19 vaccine received a week earlier. Electrocardiogram showed T inversion in V1-V3, III, and aVF, while 24-hour Holter monitoring revealed frequent ventricular premature beats. A transthoracic echocardiogram showed severe biventricular dilation and mild left ventricular (LV) dysfunction. Cardiac magnetic resonance (CMR) imaging confirmed these findings, showing moderate right ventricular (RV) systolic dysfunction with akinesia of the inferior and inferolateral walls. T2 hypersignal in the middle segment of the inferior inferior interventricular septum suggested myocardial edema. Extensive transmural late gadolinium enhancement was noted in the RV and LV walls. An implantable loop recorder was implanted. Three months later, the patient was admitted with palpitations, fever, and a positive SARS-CoV-2 test. Sustained ventricular tachycardia (VT) episodes were documented and managed with amiodarone and β-blockers. Follow-up CMR showed a slight improvement in LV ejection fraction and resolution of edema. A single-chamber implantable cardioverter-defibrillator (ICD) was implanted. Genetic testing for arrhythmogenic RV cardiomyopathy (ARVC) was negative, and family screening was normal. Two years later, pre-syncope episodes occurred, and ICD interrogation revealed nonsustained VT. The patient is awaiting VT ablation. This case highlights the diagnostic and therapeutic challenges of ARVC, particularly in differentiating it from myocarditis. The "hot-phase" presentation, vaccine association, and subsequent SARS-CoV-2 infection added complexity. CMR was crucial for diagnosis, and VT management required a combination of medical therapy and invasive procedures.

Lifetime cumulative activity burden is associated with symptomatic heart failure and arrhythmic risk in patients with arrhythmogenic right ventricular cardiomyopathy: a retrospective cohort study

AIMS

Sports-related physical activity is associated with an increased risk of ventricular dysfunction and arrhythmias in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). However, there are currently no standardized strategies for activity assessment. Thresholds for harmful levels of physical activity suggested by previous studies vary substantially and neither lifetime activity burden nor continuous modelling approaches were considered.

METHODS AND RESULTS

For this single-centre retrospective study, ARVC patients were interviewed to assess sports-related and non-sports-related physical activity between the age of 10 years and the last follow-up. Activity data were aggregated to the median metabolic equivalent of task-hours (METh) per week for each year. The association between cumulative physical activity burden and clinical study endpoints was investigated using Cox regression models. A total of 124 patients (median age: 39.5 years, 48% male) were included in the analysis, of whom 93 had been diagnosed with definite ARVC. Study participants reported a median overall activity of 202.3 METh/week, with 38.7 METh/week attributed to sports-related activity. In the continuous model, cumulative overall activity burden was associated with the occurrence of symptomatic heart failure [hazard ratio (HR) per 100 METh/week: 1.017, 95% CI (1.003, 1.032), P = 0.015], sustained ventricular tachycardia [HR: 1.021, 95% CI (1.006, 1.037), P = 0.007], and implantable cardioverter defibrillator interventions [HR: 1.017, 95%CI (1.000, 1.034), P = 0.048]. This finding was consistent when considering sports-related activity separately as a predictor variable, whereas the resulting hazard ratios did not show a significant association for non-sports-related physical activity.

CONCLUSION

This study demonstrates for the first time that cumulative physical activity as a continuous predictor variable is associated with symptomatic heart failure and arrhythmic risk in ARVC patients. Collaborative research is required in larger cohorts to investigate the influence of potential confounders on event occurrence and to develop threshold recommendations for clinical practice.

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.

RESULTS

Eighty-five individuals were included. Endocardial global longitudinal strain (GLS)-epicardial GLS (GLSepi) gradient was altered predominantly in group 1, illustrating transmural strain alteration in overt ALVC (3.8 ± 1.1 in group 1, 4.3 ± 2.2 in group 2, 5.2 ± 1.2 in group 3, and 5.4 ± 1.6 in group 4; P = .0017), whereas GLSepi was impaired predominantly in group 2 (endocardial GLS and GLSepi were 15.0 ± 4.1% and 11.2 ± 3.3%, respectively, in group 1; 20.5 ± 2.8% and 16.2 ± 5.5% in group 2; 23.4 ± 3.3% and 18.2 ± 2.7% in group 3; and 24.6 ± 2.8% and 19.2 ± 1.9% in group 4; P < .0001 for all). GLSepi was able to detect subepicardial LGE in genetic variant carriers without overt ALVC with an area under curve of 0.84 (95% CI, 0.73-0.95). However, segmental epicardial and endocardial strain behaved similarly and showed comparable diagnostic values for segmental LGE detection (areas under the curve, 0.72; [95% CI, 0.69-0.76] and 0.73 [95% CI, 0.70-0.76], respectively, P = .40).

CONCLUSIONS

LSS alteration in ALVC progresses from the epicardium to the endocardium along with disease severity. Irrespective of LSS analysis, which did not provide incremental diagnostic value for the detection and localization of LGE, strain echocardiography was shown to be a potential surrogate marker of LGE, including in apparently healthy individuals with isolated LV fibrosis.

Progression of myocardial dysfunction and prediction of arrhythmic events in patients with exercise-induced arrhythmogenic cardiomyopathy

Background

Several reports exist of an acquired exercise-induced arrhythmogenic cardiomyopathy. Little is known about myocardial disease progression and arrhythmia prediction in this population.

Objective

The study sought to explore the evolution of myocardial function and structure and its relation to incident life-threatening ventricular arrhythmias (VA), to identify markers of impending events.

Methods

We included athletes (individuals with exercise doses >24 metabolic equivalent of task hours per week, >6 consecutive years, participating in organized and competitive sports) who had VA, absence of family history and known genetic variants associated with cardiac disease, and no other identified etiology, in a tertiary referral single-center, longitudinal cohort study of patients with exercise-induced arrhythmogenic cardiomyopathy (EiAC). Evolution of myocardial function and structure was assessed by repeated echocardiographic examinations during long-term follow-up. Life-threatening VA were assessed at baseline and during long-term follow-up.

Results

Forty-one EiAC patients (15% women, age 45 ± 13 years) were followed for 80 (interquartile range 48-115) months. There were no changes in myocardial function or structure in the overall population during follow-up. We observed high incidence rate and high recurrence rate of life-threatening VA in EiAC patients. Subtle deterioration of right ventricular function was strongly associated with subsequent first-time VA (odds ratio 1.12, 95% confidence interval 1.01-1.25, P = .031, per 1% deterioration of right ventricular free wall longitudinal strain).

Conclusion

There were no clear changes in myocardial function or structure during follow-up in the overall population, but there was a high incidence rate and high recurrence rate of life-threatening VA. Subtle right ventricular deterioration by free wall longitudinal strain was a strong predictor of impending first-time life-threatening VA during follow-up.

Apicolateral bulge: A potential mimic of arrhythmogenic right ventricular cardiomyopathy in a professional athlete-A case report and literature review

Soccer is the most popular sport in the world, with over 265 million active players and approximately 0.05% professional players worldwide. The Fédération Internationale de Football Association (FIFA) has made preparticipation screening recommendations which involve electrocardiography and echocardiography being performed prior to international competition. The aim of preparticipation cardiovascular screening in young athletes is to detect asymptomatic individuals with cardiovascular disease at risk of sudden cardiac death (SCD). The incidence of SCD in young athletes (age≤ 35 years) is 0.6-3.6 in 100,000 persons/year, with most deaths due to cardiovascular causes. Arrhythmogenic right ventricular cardiomyopathy (ARVC) is one of the leading causes of SCD in young athletes. It is a genetic disease characterized by progressive fibrofatty replacement of the myocardium with variable phenotypic expression. Exercise-induced cardiac remodeling in conjunction with extensive T-wave inversion raises concern for ARVC. This case report and literature review explores a potential mimic for ARVC, the role of cardiovascular screening in sport, and the use of a multimodality approach for risk stratification and management.

Advanced myocardial characterization and function with cardiac CT

Non-invasive imaging with characterization and quantification of the myocardium with computed tomography (CT) became feasible owing to recent technical developments in CT technology. Cardiac CT can serve as an alternative modality when cardiac magnetic resonance imaging and/or echocardiography are contraindicated, not feasible, inconclusive, or non-diagnostic. This review summarizes the current and potential future role of cardiac CT for myocardial characterization including a summary of late enhancement techniques, extracellular volume quantification, and strain analysis. In addition, this review highlights potential fields for research about myocardial characterization with CT to possibly include it in clinical routine in the future.

The 2023 European Task Force Criteria for Diagnosis of Arrhythmogenic Cardiomyopathy: Historical Background and Review of Main Changes

Arrhythmogenic cardiomyopathy (ACM) is a cardiac disease featured by non-ischemic myocardial scarring linked to ventricular electrical instability. As there is no single gold-standard test, diagnosing ACM remains challenging and a combination of specific criteria is needed. The diagnostic criteria were first defined and widespread in 1994 and then revised in 2010, approaching and focusing primarily on right ventricular involvement without considering any kind of left ventricular variant or phenotype. Years later, in 2020, with the purpose of overcoming previous limitations, the Padua Criteria were introduced by an international expert report. The main novel elements were the introduction of specific criteria for left ventricular variants as well as the use of cardiac magnetic resonance for tissue characterization and scar detection. The last modifications and refinement of these criteria were published at the end of 2023 as the European Task Force criteria, by a "head-quarter" of ACM international experts, proving the emerging relevance of this condition besides its difficult diagnosis. In this review, emphasizing the progress in understanding the aetiology of the cardiomyopathy, an analysis of the new criteria is presented. The introduction of the term "scarring/arrhythmogenic cardiomyopathy" sets an important milestone in this field, underlying how non-ischemic myocardial scarring-typical of ACM-and arrhythmic susceptibility could be the main pillars of numerous different phenotypic variants regardless of etiology.

The differentiation of the competitive athlete with physiologic cardiac remodeling from the athlete with cardiomyopathy

There are currently 5 million active high school, collegiate, professional, and master athletes in the United States. Regular intense exercise by these athletes can promote structural, electrical and functional remodeling of the heart, which is termed the "athlete's heart." In addition, regular intense exercise can lead to pathological adaptions that promote or worsen cardiac disease. Many of the athletes in the United States seek medical care. Consequently, physicians must be aware of the normal cardiac anatomy and physiology of the athlete, the differentiation of the normal athlete heart from the athlete with cardiomyopathy, and the contemporary care of the athlete with a cardiomyopathy. In athletes with persistent cardiovascular symptoms, investigations should include a detailed history and physical examination, an ECG, a transthoracic echocardiogram, and in athletes in whom the diagnosis is uncertain, a maximal exercise stress test or a continuous ECG recording, and cardiac magnetic resonance imaging or cardiac computed tomography angiography when definition of the coronary anatomy or characterization of the aorta and the aortic great vessels is indicated. This article discusses the differentiation of the normal athlete with physiologic cardiac remodeling from the athlete with hypertrophic, dilated or arrhythmogenic ventricular cardiomyopathy (ACM). The ECG changes in trained athletes that are considered normal, borderline, or abnormal are listed. In addition, the normal echocardiographic measurements for athletes who consistently participate in endurance, power, combined or heterogeneous sports are enumerated and discussed. Algorithms are listed that are useful in the diagnosis of trained athletes with borderline or abnormal echocardiographic measurements suggestive of cardiomyopathies along with the major and minor criteria for the diagnosis of ACM in athletes. Thereafter, the treatment of athletes with hypertrophic, dilated, and arrhythmogenic right ventricular cardiomyopathies are reviewed. The distinction between physiologic changes and pathologic changes in the hearts of athletes has important therapeutic and prognostic implications. Failure by the physician to correctly diagnose an athlete with hypertrophic cardiomyopathy, dilated cardiomyopathy, or ACM, can lead to the sudden cardiac arrest and death of the athlete during training or sports competition. Conversely, an incorrect diagnosis by a physician of cardiac pathology in a normal athlete can lead to an unnecessary restriction of athlete training and competition with resultant significant emotional, psychological, financial, and long-term health consequences in the athlete.

Reduced plakoglobin increases the risk of sodium current defects and atrial conduction abnormalities in response to androgenic anabolic steroid abuse

Androgenic anabolic steroids (AAS) are commonly abused by young men. Male sex and increased AAS levels are associated with earlier and more severe manifestation of common cardiac conditions, such as atrial fibrillation, and rare ones, such as arrhythmogenic right ventricular cardiomyopathy (ARVC). Clinical observations suggest a potential atrial involvement in ARVC. Arrhythmogenic right ventricular cardiomyopathy is caused by desmosomal gene defects, including reduced plakoglobin expression. Here, we analysed clinical records from 146 ARVC patients to identify that ARVC is more common in males than females. Patients with ARVC also had an increased incidence of atrial arrhythmias and P wave changes. To study desmosomal vulnerability and the effects of AAS on the atria, young adult male mice, heterozygously deficient for plakoglobin (Plako+/-), and wild type (WT) littermates were chronically exposed to 5α-dihydrotestosterone (DHT) or placebo. The DHT increased atrial expression of pro-hypertrophic, fibrotic and inflammatory transcripts. In mice with reduced plakoglobin, DHT exaggerated P wave abnormalities, atrial conduction slowing, sodium current depletion, action potential amplitude reduction and the fall in action potential depolarization rate. Super-resolution microscopy revealed a decrease in NaV1.5 membrane clustering in Plako+/- atrial cardiomyocytes after DHT exposure. In summary, AAS combined with plakoglobin deficiency cause pathological atrial electrical remodelling in young male hearts. Male sex is likely to increase the risk of atrial arrhythmia, particularly in those with desmosomal gene variants. This risk is likely to be exaggerated further by AAS use. KEY POINTS: Androgenic male sex hormones, such as testosterone, might increase the risk of atrial fibrillation in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC), which is often caused by desmosomal gene defects (e.g. reduced plakoglobin expression). In this study, we observed a significantly higher proportion of males who had ARVC compared with females, and atrial arrhythmias and P wave changes represented a common observation in advanced ARVC stages. In mice with reduced plakoglobin expression, chronic administration of 5α-dihydrotestosterone led to P wave abnormalities, atrial conduction slowing, sodium current depletion and a decrease in membrane-localized NaV1.5 clusters. 5α-Dihydrotestosterone, therefore, represents a stimulus aggravating the pro-arrhythmic phenotype in carriers of desmosomal mutations and can affect atrial electrical function.

What is the most appropriate age for the first cardiac screening of athletes?

For sporting organisations that conduct screening of athletes, there are very few consistent guidelines on the age at which to start. Our review found the total rate of sudden cardiac arrest or death is very low between the ages of 8-11 years (less than 1/100,000/year), increasing to 1-2/100,000/year in both elite athletes and community athletes aged 12-15 years and then steadily increases with age. The conditions associated with sudden cardiac death in paediatric athletes and young adult athletes are very similar with some evidence that death from coronary artery abnormalities occurs more frequently in athletes 10-14 years old. The decision when to begin a screening program involves a complex interplay between requirements and usual practices in a country, the rules of different leagues and programs, the age of entry into an elite program, the underlying risk of the population and the resources available. Given the incidence of sudden cardiac arrest or death in young people, we recommend beginning cardiac screening no earlier than 12 years (not later than 16 years). The risk increases with age, therefore, starting a program at any point after age 12 has added value. Importantly, anyone with concerning symptoms (e.g. collapse on exercise) or family history of an inherited cardiac condition should see a physician irrespective of age. Finally, no screening program can capture all abnormalities, and it is essential for organisations to implement a cardiac emergency plan including training on recognition and response to sudden cardiac arrest and prompt access to resuscitation, including defibrillators.

Correlation between Epsilon Wave and Late Potentials in Arrhythmogenic Right Ventricular Cardiomyopathy-Do Late Potentials Define the Epsilon Wave?

Introduction: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disorder characterised by progressive fibrosis predominantly of the right ventricular (RV) myocardium, resulting in life-threatening arrhythmias and heart failure. The diagnosis is challenging due to a wide spectrum of clinical symptoms. The important role of ECG was covered in the current diagnostic criteria. The role of the epsilon wave (EW) is still under discussion. Aim: The aim of the study was to examine a potential association between the EW and late ventricular potentials (LPs) in ARVC patients (pts). The correlation between RV dilatation or dysfunction and LPs/EW was also analysed. Methods: The ARVC group consisted of 81 pts (53 men, aged 20-78 years) fulfilling 2010 International Task Force Criteria. 12-lead ECG, LPs, Holter, and ECHO were performed in all pts. The presence of EW was analysed in ECG by 3 investigators. LPs were detected by signal-averaged ECG (SAECG). SAECG was considered positive for LPs when at least two of the three following criteria were met: (1) the filtered QRS duration (fQRS) ≥ 114 msec; (2) the duration of the final QRS fragment in which low-amplitude signals lower than 40 μV are recorded (LAS-40 > 38 msec); and (3) the root mean square amplitude of the last 40 milliseconds of the fQRS complex (RMS-40 < 20 μV). The results were compared with a reference group consisting of 53 patients with RV damage in the course of atrial septum defect (ASD) or Ebstein's Anomaly (EA). Results: In the ARVC group, a significant relationship was observed between the occurrence of EW and the presence of LPs. EW was more common in the LP+ than in the LP- patients (48.1% vs. 6.9%, p < 0001; OR 12.5; 95% CI [2.691-58.063]). In ARVC pts, RVOT > 36 mm, RVIT > 41 mm, and RV S' < 9 cm/s were observed significantly more often in the LPs+ than in the LPs- group (OR [95% CI]: 8.3 [2.9-1.5], 6.4 [2.2-19.0] and 3.6 [1.1-12.2], respectively). In the ARVC group, any of fQRS > 114 ms, LAS > 38 ms, and RMS < 20 μV were significantly more frequent in EW+ pts. In multivariate analysis, the independent factors of the EW were LAS-40 and RV S'. In the LPs- subgroup, RVOT > 36 mm was more frequent in ASD/EA than in ARVC (70.4% vs. 25%, p = 0.002). Similarly, in the LPs- subgroup, RVIT > 41 mm was encountered more frequently in ASD/EA than in ARVC (85.2% vs. 48.3%, p = 0.004). Conclusions: In ARVC, there is an association between EW and LPs, with both probably resulting from the same process of fibrofatty substitution of the RV myocardium. Although RV dilatation is common in ASD and EA, it does not correlate with LPs.

A novel tool for arrhythmic risk stratification in desmoplakin gene variant carriers

BACKGROUND AND AIMS

Pathogenic desmoplakin (DSP) gene variants are associated with the development of a distinct form of arrhythmogenic cardiomyopathy known as DSP cardiomyopathy. Patients harbouring these variants are at high risk for sustained ventricular arrhythmia (VA), but existing tools for individualized arrhythmic risk assessment have proven unreliable in this population.

METHODS

Patients from the multi-national DSP-ERADOS (Desmoplakin SPecific Effort for a RAre Disease Outcome Study) Network patient registry who had pathogenic or likely pathogenic DSP variants and no sustained VA prior to enrolment were followed longitudinally for the development of first sustained VA event. Clinically guided, step-wise Cox regression analysis was used to develop a novel clinical tool predicting the development of incident VA. Model performance was assessed by c-statistic in both the model development cohort (n = 385) and in an external validation cohort (n = 86).

RESULTS

In total, 471 DSP patients [mean age 37.8 years, 65.6% women, 38.6% probands, 26% with left ventricular ejection fraction (LVEF) < 50%] were followed for a median of 4.0 (interquartile range: 1.6-7.3) years; 71 experienced first sustained VA events {2.6% [95% confidence interval (CI): 2.0, 3.5] events/year}. Within the development cohort, five readily available clinical parameters were identified as independent predictors of VA and included in a novel DSP risk score: female sex [hazard ratio (HR) 1.9 (95% CI: 1.1-3.4)], history of non-sustained ventricular tachycardia [HR 1.7 (95% CI: 1.1-2.8)], natural logarithm of 24-h premature ventricular contraction burden [HR 1.3 (95% CI: 1.1-1.4)], LVEF < 50% [HR 1.5 (95% CI: .95-2.5)], and presence of moderate to severe right ventricular systolic dysfunction [HR 6.0 (95% CI: 2.9-12.5)]. The model demonstrated good risk discrimination within both the development [c-statistic .782 (95% CI: .77-.80)] and external validation [c-statistic .791 (95% CI: .75-.83)] cohorts. The negative predictive value for DSP patients in the external validation cohort deemed to be at low risk for VA (<5% at 5 years; n = 26) was 100%.

CONCLUSIONS

The DSP risk score is a novel model that leverages readily available clinical parameters to provide individualized VA risk assessment for DSP patients. This tool may help guide decision-making for primary prevention implantable cardioverter-defibrillator placement in this high-risk population and supports a gene-first risk stratification approach.

Improved diagnosis of arrhythmogenic right ventricular cardiomyopathy using electrocardiographic deep learning

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare genetic heart disease associated with life-threatening ventricular arrhythmias. Diagnosis of ARVC is based on the 2010 Task Force Criteria (TFC), application of which often requires clinical expertise at specialized centers.

OBJECTIVE

The purpose of this study was to develop and validate an electrocardiogram (ECG) deep learning (DL) tool for ARVC diagnosis.

METHODS

ECGs of patients referred for ARVC evaluation were used to develop (n = 551 [80.1%]) and test (n = 137 [19.9%]) an ECG-DL model for prediction of TFC-defined ARVC diagnosis. The ARVC ECG-DL model was externally validated in a cohort of patients with pathogenic or likely pathogenic (P/LP) ARVC gene variants identified through the Geisinger MyCode Community Health Initiative (N = 167).

RESULTS

Of 688 patients evaluated at Johns Hopkins Hospital (JHH) (57.3% male, mean age 40.2 years), 329 (47.8%) were diagnosed with ARVC. Although ARVC diagnosis made by referring cardiologist ECG interpretation was unreliable (c-statistic 0.53; confidence interval [CI] 0.52-0.53), ECG-DL discrimination in the hold-out testing cohort was excellent (0.87; 0.86-0.89) and compared favorably to that of ECG interpretation by an ARVC expert (0.85; 0.84-0.86). In the Geisinger cohort, prevalence of ARVC was lower (n = 17 [10.2%]), but ECG-DL-based identification of ARVC phenotype remained reliable (0.80; 0.77-0.83). Discrimination was further increased when ECG-DL predictions were combined with non-ECG-derived TFC in the JHH testing (c-statistic 0.940; 95% CI 0.933-0.948) and Geisinger validation (0.897; 95% CI 0.883-0.912) cohorts.

CONCLUSION

ECG-DL augments diagnosis of ARVC to the level of an ARVC expert and can differentiate true ARVC diagnosis from phenotype-mimics and at-risk family members/genotype-positive individuals.

Natural Course of Electrocardiographic Features in Arrhythmogenic Right Ventricular Cardiomyopathy and Their Relation to Ventricular Arrhythmic Events

BACKGROUND

Electrocardiographic abnormalities are common in arrhythmogenic right ventricular cardiomyopathy and are included in the 2010 Task Force Criteria. Their time course, however, remains uncertain. In this retrospective observational study, we aimed to assess the long-term evolution of electrocardiographic characteristics and their relation to ventricular arrhythmias.

METHODS AND RESULTS

Three hundred fifty-three patients with arrhythmogenic right ventricular cardiomyopathy as per the 2010 Task Force Criteria with 6871 automatically processed 12-lead digital ECGs were included. The relationship between the electrocardiographic parameters and the risk of ventricular arrhythmias was assessed at 10 years from the first ECG. Electrocardiographic parameters were compared between the first contact ECG, the ECG at diagnosis, and the most recent ECG. Median time between the first and the latest ECG was 6 [interquartile range, 1-14] years. Reductions of QRS voltage, R- and T-wave amplitudes between the first, diagnostic, and the latest ECGs were observed across precordial and extremity leads. Mean QRS duration increased from 96 to 102 ms (P<0.001), terminal activation duration (V1) from 47 to 52 ms (P<0.001), and QTc from 419 to 432 ms (P<0.001). T-wave inversions in leads V3 to V6 and aVF at first ECG were associated with ventricular arrhythmias (adjusted hazard ratio [HRadj][V3], 2.03 [95% CI, 1.23-3.34] and HRadj[aVF], 1.87 [95% CI, 1.13-3.08]).

CONCLUSIONS

Depolarization and repolarization parameters evolved over time in patients with arrhythmogenic right ventricular cardiomyopathy, supporting the progressive nature of arrhythmogenic right ventricular cardiomyopathy. Electrocardiographic abnormalities may be detected before diagnosis and might, although not fulfilling the 2010 Task Force Criteria, be markers of early disease. T-wave inversion in leads V3 or aVF before diagnosis was associated with ventricular arrhythmias during follow-up.

Multimodality imaging in arrhythmogenic cardiomyopathy - From diagnosis to management

Arrhythmogenic Cardiomyopathy (AC), an inherited cardiac disorder characterized by myocardial fibrofatty replacement, carries a significant risk of sudden cardiac death (SCD) due to ventricular arrhythmias. A comprehensive multimodality imaging approach, including echocardiography, cardiac magnetic resonance imaging (CMR), and cardiac computed tomography (CCT), allows for accurate diagnosis, effective risk stratification, vigilant monitoring, and appropriate intervention, leading to improved patient outcomes and the prevention of SCD. Echocardiography is primary tool ventricular morphology and function assessment, CMR provides detailed visualization, CCT is essential in early stages for excluding congenital anomalies and coronary artery disease. Echocardiography is preferred for follow-up, with CMR capturing changes over time. The strategic use of these imaging methods aids in confirming AC, differentiating it from other conditions, tracking its progression, managing complications, and addressing end-stage scenarios.

Diagnostic value of late gadolinium enhancement at cardiovascular magnetic resonance to distinguish arrhythmogenic right ventricular cardiomyopathy from differentials

BACKGROUND

While late gadolinium enhancement (LGE) is proposed as a diagnostic criterion for arrhythmogenic right ventricular cardiomyopathy (ARVC), the potential of LGE to distinguish ARVC from differentials remains unknown. We aimed to assess the diagnostic value of LGE for ARVC diagnosis.

METHODS

We included 132 subjects (60% male, 47 ± 11 years) who had undergone cardiac magnetic resonance imaging with LGE assessment for ARVC or ARVC differentials. ARVC was diagnosed as per 2010 Task Force Criteria (n = 55). ARVC differentials consisted of familial/genetic dilated cardiomyopathy (n = 25), myocarditis (n = 13), sarcoidosis (n = 20), and amyloidosis (n = 19). The diagnosis of all differentials was based on the most current standard of reference. The presence of LGE was evaluated using a 7-segment right ventricle (RV) and 17-segment left ventricle (LV) model. Subsequently, we assessed LGE patterns for every patient individually for fulfilling LV- and/or RV-LGE per Padua criteria, independent of their clinical diagnosis (i.e. phenotype). Diagnostic values were analyzed using sensitivity and specificity for any RV-LGE, any LV-LGE, RV-LGE per Padua criteria, and prevalence graphs for LV-LGE per Padua criteria. The optimal integration of LGE for ARVC diagnosis was determined using classification and regression tree analysis.

RESULTS

One-third (38%) of ARVC patients had RV-LGE, while half (51%) had LV-LGE. RV-LGE was less frequently observed in ARVC vs non-ARVC patients (38% vs 58%, p = 0.034) leading to a poor discriminatory potential (any RV-LGE: sensitivity 38%, specificity 42%; RV-LGE per Padua criteria: sensitivity 36%, specificity 44%). Compared to ARVC patients, non-ARVC patients more often had LV-LGE (91% vs 51%, p < 0.001) which was also more globally distributed (median 9 [interquartile range (IQR): 3-13] vs 0 [IQR: 0-3] segments, p < 0.001). The absence of anteroseptal and absence of extensive (≥5 segments) mid-myocardial LV-LGE, and absence of moderate (≥2 segments) mid-myocardial LV-LGE predicted ARVC with good diagnostic performance (sensitivity 93%, specificity 78%).

CONCLUSION

LGE is often present in ARVC differentials and may lead to false positive diagnoses when used without knowledge of LGE patterns. Moderate RV-LGE without anteroseptal and mid-myocardial LV-LGE is typically observed in ARVC.

Demonstration of Arrhythmia Substrate-Associated Dispersion of Repolarization by Epicardial Unipolar Mapping in Brugada Syndrome

BACKGROUND

Epicardial unipolar mapping has not been thoroughly investigated in Brugada syndrome (BrS).

OBJECTIVES

This study aims to examine the characteristics of epicardial unipolar potentials in BrS and investigate the differences from overt cardiomyopathy.

METHODS

Epicardial mapping was performed in 8 patients with BrS and 6 patients with cardiomyopathy. We investigated the J-wave amplitudes using unipolar recordings at delayed potential (DP) sites via bipolar recordings. The repolarization time (RT) at and around the DP recording sites was measured, and maximum dispersion of the RT divided by the distance was defined as the RT dispersion index.

RESULTS

Epicardial mapping at baseline revealed significantly higher J-wave amplitude with bipolar DP in patients with BrS than in patients with cardiomyopathy. J-wave amplitude ≥0.42 mV had 99.1% sensitivity and 100% specificity for diagnosing BrS. The RT dispersion index was significantly higher in patients with BrS than in patients with cardiomyopathy at baseline. In all patients with BrS, coved-type unipolar electrograms without negative T waves (short RT) appeared close to coved-type electrograms with negative T waves (long RT) at the DP recording sites after pilsicainide administration. Thus, a steep RT dispersion was observed in this region, and ventricular arrhythmias emerged from this shorter RT area in all 3 patients with BrS in whom ventricular arrhythmias were induced.

CONCLUSIONS

Bipolar DP-related prominent unipolar J waves and steep repolarization gradients may be more specific for characterizing BrS than for overt cardiomyopathy. Ventricular arrhythmias in BrS are associated with a steep repolarization gradient, indicating phase 2 re-entry as a possible cause.

Diagnostic and Prognostic Value of Right Ventricular Fat Quantification from Computed Tomography in Arrhythmogenic Right Ventricular Cardiomyopathy

Background: In arrhythmogenic right ventricular cardiomyopathy (ARVC) non-invasive scar evaluation is not included among the diagnostic criteria or the predictors of ventricular arrhythmias (VA) and sudden death (SD). Computed tomography (CT) has excellent spatial resolution and allows a clear distinction between myocardium and fat; thus, it has great potential for the evaluation of myocardial scar in ARVC. Objective: The objective of this study is to evaluate the feasibility, and the diagnostic and prognostic value of semi-automated quantification of right ventricular (RV) fat replacement from CT images. Methods: An observational case-control study was carried out including 23 patients with a definite (19) or borderline (4) ARVC diagnosis and 23 age- and sex-matched controls without structural heart disease. All patients underwent contrast-enhanced cardiac CT. RV images were semi-automatically reconstructed with the ADAS-3D software (ADAS3D Medical, Barcelona, Spain). A fibrofatty scar was defined as values of Hounsfield Units (HU) <-10. Within the scar, a border zone (between -10 HU and -50 HU) and dense scar (<-50 HU) were distinguished. Results: All ARVC patients had an RV scar and all scar-related measurements were significantly higher in ARVC cases than in controls (p < 0.001). The total scar area and dense scar area showed no overlapping values between cases and controls, achieving perfect diagnostic performance (sensitivity and specificity of 100%). Among ARVC patients, 16 (70%) had experienced sustained VA or aborted SD. Among all clinical, ECG and imaging parameters, the dense scar area was the only one with a statistically significant association with VA and SD (p = 0.003). Conclusions: In ARVC, RV myocardial fat quantification from CT is feasible and may have considerable diagnostic and prognostic value.

Sequential Unipolar Biventricular Pulsed Field Ablation for Refractory Intramural Septal Ventricular Tachycardia

Catheter ablation of septal ventricular tachycardia (VT) is challenging. Pulsed field ablation is a promising technology, potentially reaching deep substrates. We report the first sequential unipolar biventricular pulsed field ablation targeting refractory septal VT. Besides, we illustrate the importance of searching underlying cardiomyopathy in patients with recurrent multiple morphology VTs and normal magnetic resonance imaging.

Right Ventricular Strain Derived from Cardiac MRI Feature Tracking for the Diagnosis and Prognosis of Arrhythmogenic Right Ventricular Cardiomyopathy

Purpose To demonstrate the myocardial strain characteristics of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC), based on revised Task Force Criteria (rTFC), and to explore the prognostic value of strain analysis in ARVC. Materials and Methods This retrospective study included 247 patients (median age, 38 years [IQR, 28-48 years]; 167 male, 80 female) diagnosed with ARVC, based on rTFC, between 2014 and 2018. Patients were divided into "possible" (n =25), "borderline" (n = 40), and "definite" (n = 182) ARVC groups following rTFC. Biventricular global strain parameters were calculated using cardiac MRI feature tracking (FT). The primary outcome was defined as a composite of cardiovascular events, including cardiovascular death, heart transplantation, and appropriate implantable cardioverter defibrillator discharge. Univariable and multivariable cumulative logistic regression and Cox proportional hazards regression analysis were used to evaluate the diagnostic and prognostic value of right ventricle (RV) strain parameters. Results Patients with definite ARVC had significantly reduced RV global strain in all three directions compared with possible or borderline groups (all P < .001). RV global longitudinal strain (GLS) was an independent predictor for disease (odds ratio, 1.09 [95% CI: 1.02, 1.16]; P = .009). During a median follow-up of 3.4 years (IQR, 2.0-4.9 years), 55 patients developed primary end point events. Multivariable analysis showed that RV GLS was independently associated with the occurrence of cardiovascular events (hazard ratio, 1.15 [95% CI: 1.07, 1.24]; P < .001). Kaplan-Meier analysis showed that patients with RV GLS worse than median had a higher risk of combined cardiovascular events (log-rank P < .001). Conclusion RV GLS derived from cardiac MRI FT demonstrated good diagnostic and prognostic value in ARVC. Keywords: MR Imaging, Image Postprocessing, Cardiac, Right Ventricle, Cardiomyopathies, Arrhythmogenic Right Ventricular Cardiomyopathy, Revised Task Force Criteria, Cardiovascular MR, Feature Tracking, Cardiovascular Events Supplemental material is available for this article. © RSNA, 2024.

2024 CSANZ Position Statement on Indications, Assessment and Monitoring of Structural and Valvular Heart Disease With Transthoracic Echocardiography in Adults

Transthoracic echocardiography (TTE) is the most widely available and utilised imaging modality for the screening, diagnosis, and serial monitoring of all abnormalities related to cardiac structure or function. The primary objectives of this document are to provide (1) a guiding framework for treating clinicians of the acceptable indications for the initial and serial TTE assessments of the commonly encountered cardiovascular conditions in adults, and (2) the minimum required standard for TTE examinations and reporting for imaging service providers. The main areas covered within this Position Statement pertain to the TTE assessment of the left and right ventricles, valvular heart diseases, pericardial diseases, aortic diseases, infective endocarditis, cardiac masses, pulmonary hypertension, and cardiovascular diseases associated with cancer treatments or cardio-oncology. Facilitating the optimal use and performance of high quality TTEs will prevent the over or under-utilisation of this resource and unnecessary downstream testing due to suboptimal or incomplete studies.

Cardiomyopathy in children: a single-centre, retrospective study of genetic and clinical characteristics

OBJECTIVES

This study aimed to describe the genetic and clinical characteristics of paediatric cardiomyopathy in a cohort of Chinese patients.

METHODS

We retrospectively reviewed the clinical history and mutation spectrum of 75 unrelated Chinese paediatric patients who were diagnosed with cardiomyopathy and referred to our hospital between January 2016 and December 2022.

RESULTS

Seventy-five children with cardiomyopathy were enrolled, including 32 (42.7%) boys and 43 (57.3%) girls. Dilated cardiomyopathy was the most prevalent cardiomyopathy (61.3%) in the patients, followed by hypertrophic cardiomyopathy (17.3%), ventricular non-compaction (14.7%), restrictive cardiomyopathy (5.3%) and arrhythmogenic right ventricular cardiomyopathy (1.3%). Whole-exome sequencing and targeted next-generation sequencing identified 34 pathogenic/likely pathogenic variants and 1 copy number variant in 14 genes related to cardiomyopathy in 30 children, accounting for 40% of all patients. TNNC1 p.Asp65Asn and MYH7 p.Glu500Lys have not been reported previously. The follow-up time ranged from 2 months to 6 years. Twenty-two children died (mortality rate 29%).

CONCLUSIONS

Comprehensive genetic testing was associated with a 40% yield of causal genetic mutations in Chinese cardiomyopathy cases. We found diversity in the mutation profile in different patients, which suggests that the mutational background of cardiomyopathy in China is heterogeneous, and the findings may be helpful to those counselling patients and families.

Identification of Potential lncRNA-miRNA-mRNA Regulatory Network Contributing to Arrhythmogenic Right Ventricular Cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) can lead to sudden cardiac death and life-threatening heart failure. Due to its high fatality rate and limited therapies, the pathogenesis and diagnosis biomarker of ARVC needs to be explored urgently. This study aimed to explore the lncRNA-miRNA-mRNA competitive endogenous RNA (ceRNA) network in ARVC. The mRNA and lncRNA expression datasets obtained from the Gene Expression Omnibus (GEO) database were used to analyze differentially expressed mRNA (DEM) and lncRNA (DElnc) between ARVC and non-failing controls. Differentially expressed miRNAs (DEmiRs) were obtained from the previous profiling work. Using starBase to predict targets of DEmiRs and intersecting with DEM and DElnc, a ceRNA network of lncRNA-miRNA-mRNA was constructed. The DEM and DElnc were validated by real-time quantitative PCR in human heart tissue. Protein-protein interaction network and weighted gene co-expression network analyses were used to identify hub genes. A logistic regression model for ARVC diagnostic prediction was established with the hub genes and their ceRNA pairs in the network. A total of 448 DEMs (282 upregulated and 166 downregulated) were identified, mainly enriched in extracellular matrix and fibrosis-related GO terms and KEGG pathways, such as extracellular matrix organization and collagen fibril organization. Four mRNAs and two lncRNAs, including COL1A1, COL5A1, FBN1, BGN, XIST, and LINC00173 identified through the ceRNA network, were validated by real-time quantitative PCR in human heart tissue and used to construct a logistic regression model. Good ARVC diagnostic prediction performance for the model was shown in both the training set and the validation set. The potential lncRNA-miRNA-mRNA regulatory network and logistic regression model established in our study may provide promising diagnostic methods for ARVC.

Genome-first evaluation with exome sequence and clinical data uncovers underdiagnosed genetic disorders in a large healthcare system

Population-based genomic screening may help diagnose individuals with disease-risk variants. Here, we perform a genome-first evaluation for nine disorders in 29,039 participants with linked exome sequences and electronic health records (EHRs). We identify 614 individuals with 303 pathogenic/likely pathogenic or predicted loss-of-function (P/LP/LoF) variants, yielding 644 observations; 487 observations (76%) lack a corresponding clinical diagnosis in the EHR. Upon further investigation, 75 clinically undiagnosed observations (15%) have evidence of symptomatic untreated disease, including familial hypercholesterolemia (3 of 6 [50%] undiagnosed observations with disease evidence) and breast cancer (23 of 106 [22%]). These genetic findings enable targeted phenotyping that reveals new diagnoses in previously undiagnosed individuals. Disease yield is greater with variants in penetrant genes for which disease is observed in carriers in an independent cohort. The prevalence of P/LP/LoF variants exceeds that of clinical diagnoses, and some clinically undiagnosed carriers are discovered to have disease. These results highlight the potential of population-based genomic screening.

The rare cause of ST segment elevation in left precordial leads - Diagnostic clues from subtle waveforms

We report a case of ST segment elevation in left precordial leads with a convex shape caused by a rare etiology. By carefully analyzing the electrocardiogram (leads I, II, V3 to V9) of a patient with convex ST segment elevation in the left-sided chest leads, relevant etiological clues were derived. The findings were further supported by cardiac ultrasound and cardiac magnetic resonance imaging, ruling out other common causes. Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) was postulated as the underlying cause, and potential mechanisms were discussed. The diagnosis was further confirmed through a follow-up period of over three years.