Clinical utility of endomyocardial biopsies in the diagnosis of arrhythmogenic right ventricular cardiomyopathy in children

Arrhythmogenic Right Ventricular Cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) encompasses a group of conditions characterized by right ventricular fibrofatty infiltration, with a predominant arrhythmic presentation. First described in the late 1970s and early 1980s, it is now frequently recognized to have biventricular involvement. The prevalence is ∼1:2,000 to 1:5,000, depending on geographic location, and it has a slight male predominance. The diagnosis of ARVC is determined on the basis of fulfillment of task force criteria incorporating electrophysiological parameters, cardiac imaging findings, genetic factors, and histopathologic features. Risk stratification of patients with ARVC aims to identify those who are at increased risk of sudden cardiac death or sustained ventricular tachycardia. Factors including age, sex, electrophysiological features, and cardiac imaging investigations all contribute to risk stratification. The current management of ARVC includes exercise restriction, β-blocker therapy, consideration for implantable cardioverter-defibrillator insertion, and catheter ablation. This review summarizes our current understanding of ARVC and provides clinicians with a practical approach to diagnosis and management.

Clinical Characteristics and Follow-Up of Pediatric-Onset Arrhythmogenic Right Ventricular Cardiomyopathy

OBJECTIVES

The goal of this study was to describe characteristics, cascade screening results, and predictors of adverse outcome in pediatric-onset arrhythmogenic right ventricular cardiomyopathy (ARVC).

BACKGROUND

Although ARVC is increasingly recognized in children, pediatric ARVC cohorts remain underrepresented in the literature.

METHODS

This study included 12 probands with pediatric-onset ARVC (aged <18 years at diagnosis) and 68 pediatric relatives (aged <18 years at first evaluation) referred for cascade screening. ARVC diagnosis was based on 2010 Task Force Criteria. Clinical presentation, diagnostic testing, and outcomes (sustained ventricular tachycardia [VT]; heart failure) were ascertained. Predictors of adverse outcome were determined by using univariable logistic regression.

RESULTS

Pediatric-onset ARVC was diagnosed in 12 probands and 12 (18%) relatives at a median age of 16.6 years (interquartile range: 13.8-17.4 years), whereas 12 (18%) relatives reached ARVC diagnosis as adults (median age, 22.0 years; interquartile range: 20.0-26.7 years). Sudden cardiac death/arrest was the first disease manifestation in 3 (25%) probands and 3 (4%) relatives. In patients without ARVC diagnosis at presentation (n = 61), electrocardiogram and Holter monitoring abnormalities occurred before development of imaging Task Force Criteria (7.3 ± 5.0 years vs 8.4 ± 5.0 years). Clinical course was characterized by sustained VT (91%) and heart failure (36%) in probands, which were rare in relatives (2% and 0%, respectively). Male sex (P < 0.01), T-wave inversion V₁-V₃ (P < 0.01), premature ventricular complexes/runs (P ≤ 0.01), and decrease in biventricular ejection fraction (P ≤ 0.01) were associated with VT occurrence.

CONCLUSIONS

Pediatric ARVC carries high arrhythmic risk, especially in probands. Disease progression is particularly observed on electrocardiogram or Holter monitoring. Arrhythmic events are associated with male sex, T-wave inversions, premature ventricular complexes/runs, and reduced biventricular ejection fraction.

Arrhythmogenic cardiomyopathy in children according to "Padua criteria": Single pediatric center experience

INTRODUCTION

The aim of this study was to report clinical and arrhythmic features in a pediatric population affected by arrhythmogenic cardiomyopathy (ACM). Moreover, we assessed the concordance between the 2010 International Task Force criteria (ITF) and the 2020 Padua criteria.

METHODS

Inclusion criteria were "definite" or "borderline" ACM diagnosed according to the "Padua criteria" in patients <18 years old. History, electrocardiograms, ECG-holter monitorings, exercise testings, imaging investigations, electrophysiological studies, genetic testings and follow-up data were collected.

RESULTS

We enrolled 21 patients (mean age 13.9 ± 2 years). Most of them presented for minor arrhythmias. Premature ventricular complexes burden was 7.9 ± 10%. Cardiac magnetic resonance (19/21, 90.5% patients) showed right ventricular (RV) dilatation, wall motion abnormalities and late gadolinium enhancement (LGE) of both ventricles as predominant features [in 9 patients (52.9%) LGE left ventricle]. Genetic results (19/21 patient) showed compound heterozygous variants in 3/19 patients (15.8%), digenic in 3/19 (15.8%) and single in 6/19 (31.6%). Cardiac defibrillator (ICD) was indicated in 15 patients (71.4%): 6 in class I, 7 in class IIa, 2 in class IIb. Appropriate shocks occurred in 2 patients (13.3%), follow-up 5.46 ± 3.17 years According to 2010 ITF criteria: among the 18 patients with a "definite" ACM diagnosis, one patient would have had a "borderline" diagnosis, three a "possible" diagnosis and one no diagnosis and among the three patients with "borderline" diagnosis two would have had a "possible" diagnosis.

CONCLUSIONS

Pediatric ACM can be diagnosed in the majority of cases secondary to incidental finding of simple ventricular arrhythmias. PVC burden is low and exercise induced arrhythmias rarely occur. Few patients with ICD experience appropriate shocks. "Padua criteria" improve the diagnostic accuracy.

Arrhythmogenic Right Ventricular Cardiomyopathy in Pediatric Patients: An Important but Underrecognized Clinical Entity

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy characterized by fibrofatty infiltration of predominantly the right ventricular (RV) myocardium. Affected patients typically present as young adults with hemodynamically stable ventricular tachycardia, although pediatric cases are increasingly recognized. These young subjects often have a more severe phenotype with a high risk of sudden cardiac death (SCD) and progression toward heart failure. Diagnosis of ARVC is made by combining multiple sources of information as prescribed by the consensus-based Task Force Criteria. The description of Naxos disease, a fully penetrant autosomal recessive disorder that is associated with ARVC and a cutaneous phenotype of palmoplantar keratoderma and wooly hair facilitated the identification of the genetic cause of ARVC. At present, approximately 60% of patients are found to carry a pathogenic variant in one of five genes associated with the cardiac desmosome. The incomplete penetrance and variable expressivity of these variants however implies an important role for environmental factors, of which participation in endurance exercise is a strong risk factor. Since there currently is no definite cure for ARVC, disease management is directed toward symptom reduction, delay of disease progression, and prevention of SCD. This clinically focused review describes the spectrum of ARVC among children and adolescents, the genetic architecture underlying this disease, the cardio-cutaneous syndromes that led to its identification, and current diagnostic and therapeutic strategies in pediatric ARVC subjects.