Arrhythmogenic right ventricular cardiomyopathy

Sudden death of an athlete with concealed arrhythmogenic cardiomyopathy

We report the case of a professional soccer athlete who died suddenly due to early arrhythmogenic cardiomyopathy that was not diagnosed at the time of preparticipation screening. Exercise testing had repeatedly shown effort-induced premature ventricular beats with normal echocardiography, a finding that was considered reassuring. However, there is emerging evidence that cardiac diseases characterized by focal ventricular scarring may not cause wall motion abnormalities and can be revealed only by tissue characterization with cardiac magnetic resonance. Modern interpretation of premature ventricular beats features is essential to select athletes who should undergo advanced cardiac imaging investigations to achieve a correct diagnosis and sport eligibility.

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.

Cardiac Magnetic Resonance Imaging in the Evaluation of Functional Impairments in the Right Heart

Cardiac magnetic resonance (cMRI) imaging has recently become essential in cardiology. cMRI is widely recognized as the most reliable imaging technique for assessing the size and performance of the right ventricle. It allows for objective and functional cardiac tissue evaluations. Early in disease progression, cardiac structure and activity decrease subclinically. Late-phase clinically visible signs have been associated with less favourable outcomes. Subclinical alterations ought to be recognized for rapid evaluations and accurate treatment. An increasing amount of evidence supports cMRI deformation parameter quantification. Strain imaging enables cardiologists to assess heart function beyond traditional measurements. Prognostic information for cardiovascular disease patients is obtained through the right ventricle (RV) strain, including information primarily about the left ventricle (LV). Right atrial (RA) function evaluations using RA strain have been promising in recent studies. Therefore, this narrative review aims to present an overview of the data that are currently available for assessing right myocardial strain and biomechanics using cMRI.

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.

A Comprehensive Analysis of Non-Desmosomal Rare Genetic Variants in Arrhythmogenic Cardiomyopathy: Integrating in Padua Cohort Literature-Derived Data

Arrhythmogenic cardiomyopathy (ACM) is an inherited myocardial disease at risk of sudden death. Genetic testing impacts greatly in ACM diagnosis, but gene-disease associations have yet to be determined for the increasing number of genes included in clinical panels. Genetic variants evaluation was undertaken for the most relevant non-desmosomal disease genes. We retrospectively studied 320 unrelated Italian ACM patients, including 243 cases with predominant right-ventricular (ARVC) and 77 cases with predominant left-ventricular (ALVC) involvement, who did not carry pathogenic/likely pathogenic (P/LP) variants in desmosome-coding genes. The aim was to assess rare genetic variants in transmembrane protein 43 (TMEM43), desmin (DES), phospholamban (PLN), filamin c (FLNC), cadherin 2 (CDH2), and tight junction protein 1 (TJP1), based on current adjudication guidelines and reappraisal on reported literature data. Thirty-five rare genetic variants, including 23 (64%) P/LP, were identified in 39 patients (16/243 ARVC; 23/77 ALVC): 22 FLNC, 9 DES, 2 TMEM43, and 2 CDH2. No P/LP variants were found in PLN and TJP1 genes. Gene-based burden analysis, including P/LP variants reported in literature, showed significant enrichment for TMEM43 (3.79-fold), DES (10.31-fold), PLN (117.8-fold) and FLNC (107-fold). A non-desmosomal rare genetic variant is found in a minority of ARVC patients but in about one third of ALVC patients; as such, clinical decision-making should be driven by genes with robust evidence. More than two thirds of non-desmosomal P/LP variants occur in FLNC.

Right ventricular scalloping index as cardiac magnetic resonance-derived marker for diagnosis of arrhythmogenic right ventricular cardiomyopathy

BACKGROUND

The cardiac magnetic resonance (CMR) evaluation of right ventricular (RV) morphologic abnormalities in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) is subjective. Here, we aimed to use a quantitative index, the right ventricular scalloping index (RVSI), to standardize the measurement of RV free wall scalloping and aid in the imaging diagnosis.

METHODS

We retrospectively included 15 patients with definite ARVC and 45 age- and sex-matched patients with idiopathic right ventricular outflow tract ventricular arrhythmia (RVOT-VA) as controls. The RVSI was measured from cine images on four-chamber view to evaluate its ability to distinguish between ARVC and RVOT-VA patients. Other cardiac functional parameters including strain analysis were also performed.

RESULTS

The RVSI was significantly higher in the ARVC than RVOT-VA group (1.56 ± 0.23 vs 1.30 ± 0.08, p < 0.001). The diagnostic performance of the RVSI was superior to the RV global longitudinal, circumferential, and radial strains, RV ejection fraction, and RV end-diastolic volume index. The RVSI demonstrated high intraobserver and interobserver reliability (intraclass correlation coefficient, 0.94 and 0.96, respectively). RVSI was a strong discriminator between ARVC and RVOT-VA patients (area under curve [AUC], 0.91; 95% CI, 0.82-0.99). A cutoff value of RVSI ≥1.49 provided an accuracy of 90.0%, specificity of 97.8%, sensitivity of 66.7%, positive predictive value (PPV) of 90.9%, and a negative predictive value (NPV) of 89.8%. In a multivariable analysis, a family history of ARVC or sudden cardiac death (odds ratio, 38.71; 95% CI, 1.48-1011.05; p = 0.028) and an RVSI ≥1.49 (odds ratio, 64.72; 95% CI, 4.58-914.63; p = 0.002) remained predictive of definite ARVC.

CONCLUSION

RVSI is a quantitative method with good performance for the diagnosis of definite ARVC.

Multidisciplinary approach in cardiomyopathies: From genetics to advanced imaging

Cardiomyopathies are myocardial diseases characterized by mechanical and electrical dysfunction of the heart muscle which could lead to heart failure and life-threatening arrhythmias. Certainly, an accurate anamnesis, a meticulous physical examination, and an ECG are cornerstones in raising the diagnostic suspicion. However, cardiovascular imaging techniques are indispensable to diagnose a specific cardiomyopathy, to stratify the risk related to the disease and even to track the response to the therapy. Echocardiography is often the first exam that the patient undergoes, because of its non-invasiveness, wide availability, and cost-effectiveness. Cardiac magnetic resonance imaging allows to integrate and implement the information obtained with the echography. Furthermore, cardiomyopathies' genetic basis has been investigated over the years and the list of genetic mutations deemed potentially pathogenic is expected to grow further. The aim of this review is to show echocardiographic, cardiac magnetic resonance imaging, and genetic features of several cardiomyopathies: dilated cardiomyopathy (DMC), hypertrophic cardiomyopathy (HCM), arrhythmogenic cardiomyopathy (ACM), left ventricular noncompaction cardiomyopathy (LVNC), myocarditis, and takotsubo cardiomyopathy.

Myocarditis and Chronic Inflammatory Cardiomyopathy, from Acute Inflammation to Chronic Inflammatory Damage: An Update on Pathophysiology and Diagnosis

Acute myocarditis covers a wide spectrum of clinical presentations, from uncomplicated myocarditis to severe forms complicated by hemodynamic instability and ventricular arrhythmias; however, all these forms are characterized by acute myocardial inflammation. The term "chronic inflammatory cardiomyopathy" describes a persistent/chronic inflammatory condition with a clinical phenotype of dilated and/or hypokinetic cardiomyopathy associated with symptoms of heart failure and increased risk for arrhythmias. A continuum can be identified between these two conditions. The importance of early diagnosis has grown markedly in the contemporary era with various diagnostic tools available. While cardiac magnetic resonance (CMR) is valid for diagnosis and follow-up, endomyocardial biopsy (EMB) should be considered as a first-line diagnostic modality in all unexplained acute cardiomyopathies complicated by hemodynamic instability and ventricular arrhythmias, considering the local expertise. Genetic counseling should be recommended in those cases where a genotype-phenotype association is suspected, as this has significant implications for patients' and their family members' prognoses. Recognition of the pathophysiological pathway and clinical "red flags" and an early diagnosis may help us understand mechanisms of progression, tailor long-term preventive and therapeutic strategies for this complex disease, and ultimately improve clinical outcomes.

Case report: Multiple biventricular aneurysms in arrhythmogenic cardiomyopathy

Arrhythmogenic cardiomyopathy (ACM) is a genetic disease characterized by fibro-fatty myocardial replacement and is clinically associated with malignant ventricular arrhythmias and sudden cardiac death. It presents a major diagnostic and therapeutic challenge due to its complex clinical presentation and multiparametric diagnostic scoring system that includes structural, histological, and electrocardiographic data. A 57-year-old man with a history of palpitation and premature ventricular contractions (PVC) experienced syncope and sustained ventricular tachycardia at a rate of 213 bpm, which was successfully rescued by synchronized cardioversion. Multiple ventricular aneurysms were found in the right ventricular free wall and the left ventricular apical regions, as well as mild biventricular systolic dysfunction, according to echocardiography and high-frequency ultrasound. The genetic analysis revealed the following desmoplakin genes, chr6-7585274-7585275, NM_004415, exon24, and c.7780delT (p.S2594Pfs^*9), a heterozygous and likely pathogenic mutation, as the mutation sites in the patient and his 24-year-old daughter. During the 21-month follow-up, the patient did not experience syncope or pre-syncope symptoms while on β-blocker (bisoprolol) therapy. Among the multimodality imaging techniques of the ACM, late gadolinium enhancement on cardiac magnetic resonance (CMR) is accepted as a more objective indicator of myocardial fibrosis. Left ventricular systolic dysfunction, fibrosis on CMR, and frequent PVC are the primary and most sensitive clinical signs of desmoplakin cardiomyopathy. However, echocardiography continues to be the most commonly used imaging modality for assessing focal ventricular movement and structural abnormalities. The pathological characteristics of arrhythmogenic cardiomyopathy of the right ventricular anterior free wall and apical regions near the transducer can be better shown using high-frequency linear ultrasound with a higher resolution.

May Strenuous Endurance Sports Activity Damage the Cardiovascular System of Healthy Athletes? A Narrative Review

The positive effects of physical activity are countless, not only on the cardiovascular system but on health in general. However, some studies suggest a U-shape relationship between exercise volume and effects on the cardiovascular system. On the basis of this perspective, moderate-dose exercise would be beneficial compared to a sedentary lifestyle, while very high-dose physical activity would paradoxically be detrimental. We reviewed the available evidence on the potential adverse effects of very intense, prolonged exercise on the cardiovascular system, both acute and chronic, in healthy athletes without pre-existing cardiovascular conditions. We found that endurance sports activities may cause reversible electrocardiographic changes, ventricular dysfunction, and troponin elevation with complete recovery within a few days. The theory that repeated bouts of acute stress on the heart may lead to chronic myocardial damage remains to be demonstrated. However, male veteran athletes with a long sports career show an increased prevalence of cardiovascular abnormalities such as electrical conduction delay, atrial fibrillation, myocardial fibrosis, and coronary calcifications compared to non-athletes. It must be underlined that the cause-effect relationship between such abnormalities and the exercise and, most importantly, the prognostic relevance of such findings remains to be established.

Cardiac magnetic resonance imaging of arrhythmogenic cardiomyopathy: evolving diagnostic perspectives

Arrhythmogenic cardiomyopathy (ACM) is a genetically determined heart muscle disease characterized by fibro-fatty myocardial replacement, clinically associated with malignant ventricular arrhythmias and sudden cardiac death. Originally described a disease with a prevalent right ventricular (RV) involvement, subsequently two other phenotypes have been recognized, such as the left dominant and the biventricular phenotypes, for which a recent International Expert consensus document provided upgrade diagnostic criteria (the 2020 "Padua Criteria"). In this novel workup for the diagnosis of the entire spectrum of phenotypic variants of ACM, including left ventricular (LV) variants, cardiac magnetic resonance (CMR) has emerged as the cardiac imaging technique of choice, due to its capability of detailed morpho-functional and tissue characterization evaluation of both RV and LV. In this review, the key role of CMR in the diagnosis of ACM is outlined, including the supplemental value for the characterization of the disease variants. An ACM-specific CMR study protocol, as well as strengths and weaknesses of each imaging technique, is also provided. KEY POINTS: • Arrhythmogenic cardiomyopathy includes three different phenotypes: dominant right, biventricular, and dominant left. • In 2020, diagnostic criteria have been updated and cardiac magnetic resonance has emerged as the cardiac imaging technique of choice. • This aim of this review is to provide an update of the current state of art regarding the use of CMR in ACM, with a particular focus on novel diagnostic criteria, CMR protocols, and prognostic significance of CMR findings in ACM.

Sudden death of an athlete due to concealed arrhythmogenic cardiomyopathy: Why preparticipation screening did fail

We report the case of a professional soccer athlete who died suddenly for arrhythmogenic cardiomyopathy that was not diagnosed at the time of preparticipation screening. Exercise testing had repeatedly shown effort-induced premature ventricular beats with normal echocardiography, which was considered reassuring. However, there is emerging evidence that cardiac diseases characterized by focal ventricular scarring may not cause wall motion abnormalities and can be revealed only by tissue characterization with cardiac magnetic resonance. Modern interpretation of premature ventricular beats features is essential to select athletes who should undergo advanced cardiac imaging investigations, to achieve a correct diagnosis and allow safe sport participation.

Diagnostic Challenges in Rare Causes of Arrhythmogenic Cardiomyopathy—The Role of Cardiac MRI

Arrhythmogenic right ventricular dysplasia (ARVD) is a rare genetic condition of the myocardium, with a significantly high risk of sudden death. Recent genetic research and improved understanding of the pathophysiology tend to change the ARVD definition towards a larger spectrum of myocardial involvement, which includes, in various proportions, both the right (RV) and left ventricle (LV), currently referred to as ACM (arrhythmogenic cardiomyopathy). Its pathological substrate is defined by the replacement of the ventricular myocardium with fibrous adipose tissue that further leads to inadequate electrical impulses and translates into varies degrees of malignant ventricular arrythmias and dyskinetic myocardium movements. Particularly, the cardio-cutaneous syndromes of Carvajal/Naxos represent rare causes of ACM that might be suspected from early childhood. The diagnostic is sometimes challenging, even with well-established rTFC or Padua criteria, especially for pediatric patients or ACM with LV involvement. Cardiac MRI gain more and more importance in ACM diagnostic especially in non-classical forms. Furthermore, MRI is useful in highlighting myocardial fibrosis, fatty replacement or wall movement with high accuracy, thus guiding not only the depiction, but also the patient’s stratification and management.

Evolving Diagnostic Criteria for Arrhythmogenic Cardiomyopathy

Criteria for diagnosis of arrhythmogenic cardiomyopathy (ACM) were first proposed in 1994 and revised in 2010 by a Task Force. Although the Task Force criteria demonstrated a good accuracy for diagnosis of the original right ventricular phenotype (arrhythmogenic right ventricular cardiomyopathy), they lacked sensitivity for identification of the expanding phenotypic spectrum of ACM, which includes left‐sided variants and did not incorporate late‐gadolinium enhancement findings by cardiac magnetic resonance. The 2020 International criteria (“Padua criteria”) have been developed by International experts with the aim to improve the diagnosis of ACM by providing new criteria for the diagnosis of left ventricular phenotypic features. The key upgrade was the incorporation of tissue characterization findings by cardiac magnetic resonance for noninvasive detection of late‐gadolinium enhancement/myocardial fibrosis that are determinants for characterization of arrhythmogenic biventricular and left ventricular cardiomyopathy. The 2020 International criteria are heavily dependent on cardiac magnetic resonance, which has become mandatory to characterize the ACM phenotype and to exclude other diagnoses. New criteria regarding left ventricular depolarization and repolarization ECG abnormalities and ventricular arrhythmias of left ventricular origin were also provided. This article reviews the evolving approach to diagnosis of ACM, going back to the 1994 and 2010 International Task Force criteria and then grapple with the modern 2020 International criteria.

'Hot phase' clinical presentation in arrhythmogenic cardiomyopathy

Aims

The aim of this study is to evaluate the clinical features of patients affected by arrhythmogenic cardiomyopathy (AC), presenting with chest pain and myocardial enzyme release in the setting of normal coronary arteries (‘hot phase’).

Methods and results

We collected detailed anamnestic, clinical, instrumental, genetic, and histopathological findings as well as follow-up data in a series of AC patients who experienced a hot phase. A total of 23 subjects (12 males, mean age at the first episode 27 ± 16 years) were identified among 560 AC probands and family members (5%). At first episode, 10 patients (43%) already fulfilled AC diagnostic criteria. Twelve-lead electrocardiogram recorded during symptoms showed ST-segment elevation in 11 patients (48%). Endomyocardial biopsy was performed in 11 patients, 8 of them during the acute phase showing histologic evidence of virus-negative myocarditis in 88%. Cardiac magnetic resonance was performed in 21 patients, 12 of them during the acute phase; oedema and/or hyperaemia were detected in 7 (58%) and late gadolinium enhancement in 11 (92%). At the end of follow-up (mean 17 years, range 1–32), 12 additional patients achieved an AC diagnosis. Genetic testing was positive in 77% of cases and pathogenic mutations in desmoplakin gene were the most frequent. No patient complained of sustained ventricular arrhythmias or died suddenly during the ‘hot phase’.

Conclusion

‘Hot phase’ represents an uncommon clinical presentation of AC, which often occurs in paediatric patients and carriers of desmoplakin gene mutations. Tissue characterization, family history, and genetic test represent fundamental diagnostic tools for differential diagnosis.

[Clinical profile and therapeutic strategies in patients with arrhythmogenic cardiomyopathy treated in a national reference institute]

Objective

To determine the epidemiological, clinical, electrocardiographic, imaging characteristics and main therapeutic strategies performed in patients with arrhythmogenic cardiomyopathy treated in a national reference cardiovascular institute.

Materials and methods

Observational, descriptive and retrospective study that attempts to identify the clinical characteristics, complementary tests and therapeutic strategies performed in patients with arrhythmogenic cardiomyopathy treated at the Instituto Nacional Cardiovascular - INCOR EsSalud in Lima, Peru.

Results

Thirteen patients were found with arrhythmogenic cardiomyopathy. The median age at which the diagnosis was made was 38.2 years and 69.3% were male. The most frequent clinical manifestations were tachycardic palpitations (92.3%), presyncope (84.6%) and heart failure (69.2%). 23% of the patients suffered a cardiac arrest. All the patients presented at least one episode of ventricular tachycardia, 92.3% with complete left bundle branch block morphology and upper axis. 76.9% received an implantable cardioverter defibrillator (ICD), 15.3% underwent ablation and 15.3% received a heart transplant. 84.6% of the patients live to this day.

Conclusions

Arrhythmogenic cardiomyopathy predominantly affected the young and male population. All the patients had a potentially fatal ventricular arrhythmia. Biventricular disease by echocardiography and cardiac magnetic resonance occurred in 69.2% and 100% of the cases, respectively. The therapeutic strategies used were antiarrhythmic medical treatment, placement of an ICD as secondary prevention, ablation, and heart transplantation. To date, 84.6% of patients survive.

Diagnostic and prognostic value of low QRS voltages in cardiomyopathies: old but gold

The interpretation of 12-lead resting electrocardiogram (ECG) in patients with a definitive diagnosis or with the suspicion of a cardiomyopathy represents a cornerstone for the diagnostic work up and management of patients. Although low electrocardiographic QRS voltages (LQRSV) detected by 12-lead resting ECG have historically been acknowledged by physicians, in view of recent evidence on the demonstration of myocardial scar by cardiac magnetic resonance and its relevance as a cause of sudden cardiac death even in young individuals, a new interest has been raised about the utility of LQRSV in the clinical practice. Beyond their diagnostic value, LQRSV have also demonstrated a prognostic role in different cardiomyopathies. The present review summarizes the diagnostic and prognostic value of LQRSV in cardiomyopathies, reporting the new evidence, primarily based on advanced imaging studies, supporting the clinical utility of this parameter.

The Role of MicroRNAs in Arrhythmogenic Cardiomyopathy: Biomarkers or Innocent Bystanders of Disease Progression?

Arrhythmogenic cardiomyopathy (AC) is an inherited cardiac disease characterized by a progressive fibro-fatty replacement of the working myocardium and by life-threatening arrhythmias and risk of sudden cardiac death. Pathogenic variants are identified in nearly 50% of affected patients mostly in genes encoding for desmosomal proteins. AC incomplete penetrance and phenotypic variability advocate that other factors than genetics may modulate the disease, such as microRNAs (miRNAs). MiRNAs are small noncoding RNAs with a primary role in gene expression regulation and network of cellular processes. The implication of miRNAs in AC pathogenesis and their role as biomarkers for early disease detection or differential diagnosis has been the objective of multiple studies employing diverse designs and methodologies to detect miRNAs and measure their expression levels. Here we summarize experiments, evidence, and flaws of the different studies and hitherto knowledge of the implication of miRNAs in AC pathogenesis and diagnosis.

The arrhythmogenic right ventricular cardiomyopathy in comparison to the athletic heart

Intense exercise-induced right ventricular remodeling is a potential adaptation of cardiac function and structure. The features of the remodeling may overlap with those of a very early form of arrhythmogenic right ventricular cardiomyopathy (ARVC): at this early stage, it could be difficult to discriminate ARVC, from exercise-induced cardiac adaptation that may develop in normal individuals. The purpose of this paper is to discuss which exercise-induced remodeling may be a pathological or a physiological finding. A complete evaluation may be required to identify the pathological features of ARVC that would include potential risk of sudden cardiac death during sport or, to avoid the false diagnosis of ARVC. The most recent expert assessment of arrhythmogenic cardiomyopathy focuses on endurance athletes presenting with clinical features indistinguishable from ARVC.

Bone marrow contribution to the heart from development to adulthood

Cardiac chamber walls contain large numbers of non-contractile interstitial cells, including fibroblasts, endothelial cells, pericytes and significant populations of blood lineage-derived cells. Blood cells first colonize heart tissues a few days before birth, although their recruitment from the bloodstream to the cardiac interstitium is continuous and extends throughout adult life. The bone marrow, as the major hematopoietic site of adult individuals, is in charge of renewing all circulating cell types, and it therefore plays a pivotal role in the incorporation of blood cells to the heart. Bone marrow-derived cells are instrumental to tissue homeostasis in the steady-state heart, and are major effectors in cardiac disease progression. This review will provide a comprehensive approach to bone marrow-derived blood cell functions in the heart, and discuss aspects related to hot topics in the cardiovascular field like cell-based heart regeneration strategies.

Arrhythmogenic Right Ventricular Cardiomyopathy: Characterization of Left Ventricular Phenotype and Differential Diagnosis With Dilated Cardiomyopathy

Background

This study assessed the prevalence of left ventricular (LV) involvement and characterized the clinical, electrocardiographic, and imaging features of LV phenotype in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). Differential diagnosis between ARVC‐LV phenotype and dilated cardiomyopathy (DCM) was evaluated.

Methods and Results

The study population included 87 ARVC patients (median age 34 years) and 153 DCM patients (median age 51 years). All underwent cardiac magnetic resonance with quantitative tissue characterization. Fifty‐eight ARVC patients (67%) had LV involvement, with both LV systolic dysfunction and LV late gadolinium enhancement (LGE) in 41/58 (71%) and LV‐LGE in isolation in 17 (29%). Compared with DCM, the ARVC‐LV phenotype was statistically significantly more often characterized by low QRS voltages in limb leads, T‐wave inversion in the inferolateral leads and major ventricular arrhythmias. LV‐LGE was found in all ARVC patients with LV systolic dysfunction and in 69/153 (45%) of DCM patients. Patients with ARVC and LV systolic dysfunction had a greater amount of LV‐LGE (25% versus 13% of LV mass; P<0.01), mostly localized in the subepicardial LV wall layers. An LV‐LGE ≥20% had a 100% specificity for diagnosis of ARVC‐LV phenotype. An inverse correlation between LV ejection fraction and LV‐LGE extent was found in the ARVC‐LV phenotype (r=−0.63; P<0.01), but not in DCM (r=−0.01; P=0.94).

Conclusions

LV involvement in ARVC is common and characterized by clinical and cardiac magnetic resonance features which differ from those seen in DCM. The most distinctive feature of ARVC‐LV phenotype is the large amount of LV‐LGE/fibrosis, which impacts directly and negatively on the LV systolic function.

Relationship Between Electrocardiographic Findings and Cardiac Magnetic Resonance Phenotypes in Arrhythmogenic Cardiomyopathy

Background

The new designation of arrhythmogenic cardiomyopathy defines a broader spectrum of disease phenotypes, which include right dominant, biventricular, and left dominant variants. We evaluated the relationship between electrocardiographic findings and contrast‐enhanced cardiac magnetic resonance phenotypes in arrhythmogenic cardiomyopathy.

Methods and Results

We studied a consecutive cohort of patients with a definite diagnosis of arrhythmogenic cardiomyopathy, according to 2010 International Task Force criteria, who underwent electrocardiography and contrast‐enhanced cardiac magnetic resonance. Both depolarization and repolarization electrocardiographic abnormalities were correlated with the severity of dilatation/dysfunction, either global or regional, of both ventricles and the presence and regional distribution of late gadolinium enhancement. The study population included 79 patients (60% men). There was a statistically significant relationship between the presence and extent of T‐wave inversion across a 12‐lead ECG and increasing values of median right ventricular (RV) end‐diastolic volume (P<0.001) and decreasing values of RV ejection fraction (P<0.001). The extent of T‐wave inversion to lateral leads predicted a more severe RV dilatation rather than a left ventricular involvement because of the leftward displacement of the dilated RV, as evidenced by contrast‐enhanced cardiac magnetic resonance. A terminal activation delay of >55 ms in the right precordial leads (V1‐V3) was associated with higher RV volume (P=0.014) and lower RV ejection fraction (P=0.053). Low QRS voltages in limb leads predicted the presence (P=0.004) and amount (P<0.001) of left ventricular late gadolinium enhancement.

Conclusions

The study results indicated that electrocardiographic abnormalities predict the arrhythmogenic cardiomyopathy phenotype in terms of severity of RV disease and left ventricular involvement, which are among the most important determinants of the disease outcome.

Diagnostic Differentiation Between Arrhythmogenic Cardiomyopathy and Athlete's Heart by Using Imaging

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an important cause of sudden cardiac death (SCD) in youth and athletes. In the last decade, several studies focused on right ventricular (RV) remodeling in athletes and revealed that features of the physiological adaptation of the right heart to training, such as RV dilation, may overlap with those of ARVC. Therefore, a careful multiparametric evaluation is required for differential diagnosis in order to avoid false diagnosis of ARVC or, in contrast, fail to identify the risk of causing SCD. This review summarizes physiological adaptation of the RV to exercise and describes features that could help distinguishing between athlete's heart and ARVC.

Patients with Isolated Focal Right Ventricular Dyskinetic Segments: Toward a Better Understanding of This Cohort

BACKGROUND

The 2010 revised Task Force criteria for the diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) provided guidance for the classification of patients as definitive, borderline or possible ARVC. However, many patients with clinical suspicion for ARVC have isolated RV dyskinetic segments only and partly meet cardiac magnetic resonance (CMR) imaging criteria. This subgroup of patients and the implication of this imaging finding remain not well defined.

METHODS

There were 65 consecutive patients with clinical suspicion for ARVC who were referred for CMR between 2015 and 2017. The presence of fatty infiltration and fibrosis were assessed using T2 imaging and myocardial delayed enhancement sequences, respectively. RV wall motions, volumes and ejection fraction (EF) of all patients were re-analysed and quantified. Available data on family history, Holter findings, and electrocardiograms were also reviewed.

RESULTS

There were 5 patients (7.7%) that fulfilled major CMR criteria for ARVC: 4 were classified as having definitive ARVC; and 1/5 as borderline. There were 33 patients with no RV dyskinetic segments: none were classified as having definitive or borderline ARVC; 4/33 were classified as possible ARVC, leaving 29/33 as normal or no ARVC. Finally, there were 27 remaining patients (41.5%) with isolated RV dyskinetic segments: 1/27 was classified as definitive ARVC; 4/27 as borderline; 8/27 as possible; leaving 15/27 as indeterminate. Compared to control, those with isolated RV dyskinesia (including the subgroup labelled as indeterminate 15/27) had more abnormal RVEF, larger RV end-diastolic volume index (82 ± 12 mL/m² vs. 72 ± 12 mL/m², p-value 0.0127), and a trend for higher odds of dilated RV (odds ratio 3.0 [0.81–11], p-value 0.09).

CONCLUSIONS

Among patients with a clinical suspicion for ARVC, almost 40% had isolated focal RV dyskinetic segments with the majority remaining unclassified. This cohort had more RV dilation and abnormal EF compared to control.

Arrhythmogenic ventricular cardiomyopathy and sudden cardiac death: Left or right?

Arrhythmogenic right ventricular cardiomyopathy is a leading cause of sudden cardiac death among athletes in Italy and the Mediterranean region. Although it often involves the right ventricle causing scarring, dilation, systolic impairment with aneurysm formation, it can also involve the left ventricle or present as isolated left ventricular cardiomyopathy. Cardiac magnetic resonance imaging is considered the gold standard in confirming the diagnosis. We summarize four cases of arrhythmogenic ventricular cardiomyopathy with different presentations observed over the past 2 years.

Comprehensive multi-modality imaging approach in arrhythmogenic cardiomyopathy-an expert consensus document of the European Association of Cardiovascular Imaging

Arrhythmogenic cardiomyopathy (AC) is a progressive disease with high risk of life-threatening ventricular arrhythmias. A genetic mutation is found in up to 50-60% of probands, mostly affecting desmosomal genes. Diagnosis of AC is made by a combination of data from different modalities including imaging, electrocardiogram, Holter monitoring, family history, genetic testing, and tissue properties. Being a progressive cardiomyopathy, repeated cardiac imaging is needed in AC patients. Repeated imaging is important also for risk assessment of ventricular arrhythmias. This expert consensus document gives clinical recommendations for how to use multi-modality imaging in the different aspects of AC disease, including diagnosis, family screening, follow-up, risk assessment, and differential diagnosis.

Arrhythmogenic cardiomyopathy

Arrhythmogenic cardiomyopathy (AC) is a heart muscle disease clinically characterized by life-threatening ventricular arrhythmias and pathologically by an acquired and progressive dystrophy of the ventricular myocardium with fibro-fatty replacement. Due to an estimated prevalence of 1:2000-1:5000, AC is listed among rare diseases. A familial background consistent with an autosomal-dominant trait of inheritance is present in most of AC patients; recessive variants have also been reported, either or not associated with palmoplantar keratoderma and woolly hair. AC-causing genes mostly encode major components of the cardiac desmosome and up to 50 % of AC probands harbor mutations in one of them. Mutations in non-desmosomal genes have been also described in a minority of AC patients, predisposing to the same or an overlapping disease phenotype. Compound/digenic heterozygosity was identified in up to 25 % of AC-causing desmosomal gene mutation carriers, in part explaining the phenotypic variability. Abnormal trafficking of intercellular proteins to the intercalated discs of cardiomyocytes and Wnt/beta catenin and Hippo signaling pathways have been implicated in disease pathogenesis.

AC is a major cause of sudden death in the young and in athletes. The clinical picture may include a sub-clinical phase; an overt electrical disorder; and right ventricular or biventricular pump failure. Ventricular fibrillation can occur at any stage. Genotype-phenotype correlation studies led to identify biventricular and dominant left ventricular variants, thus supporting the use of the broader term AC.

Since there is no “gold standard” to reach the diagnosis of AC, multiple categories of diagnostic information have been combined and the criteria recently updated, to improve diagnostic sensitivity while maintaining specificity. Among diagnostic tools, contrast enhanced cardiac magnetic resonance is playing a major role in detecting left dominant forms of AC, even preceding morpho-functional abnormalities. The main differential diagnoses are idiopathic right ventricular outflow tract tachycardia, myocarditis, sarcoidosis, dilated cardiomyopathy, right ventricular infarction, congenital heart diseases with right ventricular overload and athlete heart. A positive genetic test in the affected AC proband allows early identification of asymptomatic carriers by cascade genetic screening of family members. Risk stratification remains a major clinical challenge and antiarrhythmic drugs, catheter ablation and implantable cardioverter defibrillator are the currently available therapeutic tools. Sport disqualification is life-saving, since effort is a major trigger not only of electrical instability but also of disease onset and progression. We review the current knowledge of this rare cardiomyopathy, suggesting a flowchart for primary care clinicians and geneticists.