Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic myocardial disease characterized by the progressive replacement of myocardial tissue with fibrofatty tissue, predisposing to the development of ventricular arrhythmias, heart failure, and sudden cardiac death.
The primary involvement concerns the right ventricle, but in more advanced forms the disease may extend to the left ventricle, resulting in so-called biventricular arrhythmogenic cardiomyopathy.
This condition is one of the main causes of sudden cardiac death in young individuals and athletes, due to the predisposition to sustained ventricular tachycardia and ventricular fibrillation. The diagnosis is complex and based on clinical, instrumental and genetic criteria, while therapy focuses on the prevention of arrhythmias and the management of heart failure.
Epidemiology
Arrhythmogenic right ventricular cardiomyopathy is a rare genetic disorder with an estimated prevalence of 1 case per 2,000–5,000 individuals, although in some populations (such as Italy and the Netherlands) it is more common.
ARVC is a genetically determined disease, transmitted in an autosomal dominant manner with variable penetrance.
The most frequently involved mutations affect the desmosomal genes, in particular:
PKP2 (Plakophilin-2): the most common mutation, present in about 40–50% of cases.
DSP (Desmoplakin): associated with more severe forms and early biventricular involvement.
JUP (Junction Plakoglobin): involved in syndromic forms such as Naxos syndrome.
DSG2 (Desmoglein-2) and DSC2 (Desmocollin-2): less frequent, but associated with variable phenotypes.
The age of onset is extremely variable, but symptoms and arrhythmias tend to appear between 10 and 50 years of age, with a peak incidence in youth. The risk of sudden death is particularly high in young subjects and athletes, especially during intense physical exercise.
Pathophysiology
Arrhythmogenic right ventricular cardiomyopathy is characterized by the progressive degeneration of the myocardium with replacement of contractile tissue by fibrosis and adiposity.
This process leads to:
Structural changes of the right ventricle: progressive dilatation, formation of aneurysms, and systolic dysfunction.
Electrical instability: predisposition to polymorphic ventricular tachycardias and ventricular fibrillation.
Disconnection of myocardial tissue: alterations of the intercellular junction due to mutations in desmosomal proteins.
Biventricular involvement: in advanced stages, the process may extend to the left ventricle, causing systolic dysfunction and clinical worsening.
Intense physical exercise accelerates myocardial damage, favoring disease progression and increasing the risk of fatal arrhythmic events. For this reason, in patients with ARVC, it is essential to avoid intense physical activity and to monitor arrhythmic risk with Holter monitoring and provocative testing.
Clinical Presentation
The clinical presentation of ARVC varies greatly, ranging from asymptomatic patients to individuals with malignant ventricular arrhythmias or advanced heart failure.
The disease develops in three main phases:
Subclinical phase: the patient is asymptomatic, but ECG abnormalities and cardiac MRI alterations may be present.
Arrhythmic phase: the patient develops ventricular extrasystoles or ventricular tachycardia, often triggered by physical exertion.
Heart failure phase: with progression toward ventricular dilatation and involvement of the left ventricle, evolving into a form of dilated cardiomyopathy.
Main signs and symptoms
Palpitations: rapid ventricular arrhythmias, often with a left bundle branch block morphology.
Syncope or presyncope: due to sustained ventricular tachycardia or ventricular fibrillation.
Dyspnea and asthenia: in patients with advanced ventricular dysfunction.
Atypical chest pain: often related to arrhythmic episodes.
Sudden cardiac death: possible initial manifestation, especially in young people and athletes.
Physical examination
Physical examination is often normal in the early stages, but in advanced cases the following may be detected:
Jugular venous distension: in patients with advanced right ventricular dysfunction.
Tricuspid regurgitation murmur: due to right ventricular dilatation.
Irregular ventricular pulsations: indicative of frequent ventricular arrhythmias.
Diagnosis
The diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) relies on clinical, electrocardiographic, imaging and genetic criteria.
In patients with suspected ARVC, instrumental tests are essential to confirm the diagnosis and stratify arrhythmic risk, including:
ECG: search for T-wave inversions in V1–V3, right bundle branch block signs, and late potentials (epsilon wave).
Holter ECG: useful for detecting frequent ventricular extrasystoles (>500 in 24 hours) or ventricular tachycardia with left bundle branch block morphology.
Echocardiogram: evaluation of right ventricular kinetics, looking for dyskinesia, ventricular aneurysms, or progressive dilatation.
Cardiac magnetic resonance imaging (CMR): key examination to document fibrofatty replacement in the myocardium, regional dysfunction, and right ventricular aneurysms.
Genetic testing: recommended to identify mutations in desmosomal genes (e.g., PKP2, DSG2, DSP), useful for family diagnosis and risk stratification.
Endomyocardial biopsy: indicated in selected cases to confirm fibrofatty replacement and structural myocardial alterations.
Diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) is based on the 2010 Task Force criteria, updated in 2020.
The diagnosis can be:
Definite: presence of 2 major criteria or 1 major + 2 minor criteria or 4 minor criteria
Probable: presence of 1 major + 1 minor criterion or 3 minor criteria
Possible: presence of 1 major criterion or 2 minor criteria
Diagnostic criteria
The criteria for defining arrhythmogenic right ventricular cardiomyopathy (ARVC) are divided into 5 classes, each with major and minor criteria.
1. Structural and functional (Imaging)
Major criteria:
MRI or echocardiography showing dilatation and dysfunction of the right ventricle, with ejection fraction <40%.
Presence of right ventricular aneurysms.
Minor criteria:
MRI or echocardiography with mild dilatation or moderate dysfunction of the right ventricle (EF 40–45%).
Segmental wall motion abnormalities of the right ventricle.
2. Histological
Major criterion: Endomyocardial biopsy demonstrating fibrofatty replacement of the myocardium.
3. Electrocardiographic
Major criteria:
Presence of epsilon wave in right precordial leads (V1–V3).
Prolonged QRS ≥110 ms in V1–V3.
Minor criteria:
T-wave inversions in V1–V3 in patients over 14 years old, in the absence of right bundle branch block.
4. Arrhythmic
Major criteria:
Sustained VT with left bundle branch block morphology.
Non-sustained VT with LBBB morphology and frequency >500 bpm in 24h.
Minor criteria:
Non-sustained VT with LBBB morphology and frequency <500 bpm in 24h.
Ventricular extrasystoles >500/24h on Holter ECG.
5. Genetic and familial
Major criterion: Presence of mutations in desmosomal genes (e.g., PKP2, DSG2, DSP).
Minor criterion: Positive family history of ARVC or sudden cardiac death under 35 years of age.
Early identification of ARVC is crucial to prevent life-threatening ventricular arrhythmias and sudden cardiac death.
Patients with borderline diagnostic criteria should be monitored over time with serial examinations to assess disease progression and the need for an implantable cardioverter-defibrillator (ICD) in high-risk subjects.
Treatment
Treatment of arrhythmogenic right ventricular cardiomyopathy (ARVC) is aimed at controlling ventricular arrhythmias, preventing sudden cardiac death, and managing ventricular dysfunction.
The therapeutic strategy depends on disease severity and the patient's arrhythmic risk.
Pharmacological therapy is indicated for prevention of ventricular arrhythmias and symptom control.
The main drugs used include:
Beta-blockers (bisoprolol, metoprolol, carvedilol): reduce sympathetic activity and the risk of ventricular arrhythmias.
Amiodarone or sotalol: indicated in patients with sustained ventricular tachycardias not controlled by beta-blockers.
ACE inhibitors and aldosterone antagonists: in patients with ventricular dysfunction to improve cardiac function.
Anticoagulants: recommended in patients with atrial fibrillation or severe right ventricular dysfunction to prevent thromboembolic events.
In patients at high risk of sudden cardiac death, implantation of an implantable cardioverter-defibrillator (ICD) is indicated.
The main indications include:
History of resuscitated cardiac arrest or sustained ventricular tachycardia.
Cardiac syncope in patients with evidence of ARVC.
Severely reduced ventricular function (EF < 35%).
High arrhythmic burden documented on Holter or exercise testing.
Radiofrequency ablation may be an option in patients with recurrent ventricular tachycardias refractory to drug therapy. However, progressive remodeling of the right ventricle may make the success of ablation transient, with a high risk of recurrence.
One of the most critical aspects in the management of ARVC is the absolute prohibition of competitive sports or intense physical exercise, even in asymptomatic patients. Physical activity can accelerate fibrofatty remodeling of the right ventricle and increase the risk of fatal ventricular arrhythmias.
In patients with advanced biventricular dysfunction and heart failure refractory to medical and interventional therapies, heart transplantation represents the only definitive therapeutic option.
Prognosis
The prognosis of ARVC is extremely variable and depends on the degree of ventricular involvement, disease progression, and arrhythmic risk.
Patients with mild, well-controlled forms may have a good quality of life, whereas those with biventricular involvement and refractory ventricular tachycardias have a high risk of adverse events.
Negative prognostic factors
History of sudden cardiac arrest or sustained ventricular tachycardia.
Early biventricular involvement (left ventricular dysfunction).
Right ventricular ejection fraction <40%.
Presence of multiple ventricular aneurysms.
Family history of sudden cardiac death.
Regular clinical follow-up and arrhythmic risk stratification are essential to optimize management and improve long-term prognosis.
Complications
The complications of ARVC mainly derive from disease progression and myocardial electrical instability. The main ones include:
Sudden cardiac death
Sudden cardiac death is the most feared complication of ARVC, especially in young people and athletes. It is caused by sustained ventricular tachycardia or untreated ventricular fibrillation. The implantable defibrillator (ICD) is the main preventive tool.
Ventricular tachycardia and ventricular fibrillation
Ventricular arrhythmias are the hallmark of ARVC. In many patients, these arrhythmias may become refractory to drug therapy, requiring transcatheter ablation or ICD implantation.
Heart failure
With disease progression, right ventricular dysfunction leads to heart failure with signs of systemic congestion (dependent edema, hepatomegaly, ascites). In more advanced cases, left ventricular involvement may lead to global heart failure.
Thromboembolic events
In patients with severe ventricular dysfunction or atrial fibrillation, the risk of pulmonary thromboembolism or ischemic stroke increases. In such cases, anticoagulant therapy is indicated.
Ventricular aneurysms
The formation of aneurysms in the right ventricle is a typical feature of advanced ARVC. Aneurysms can be foci of ventricular arrhythmias or, rarely, rupture with fatal consequences.
Conclusions
Arrhythmogenic right ventricular cardiomyopathy is a serious genetic disease with a high risk of sudden cardiac death. Early recognition, identification of high-risk patients and ICD implantation in selected individuals are key strategies to improve prognosis and prevent fatal events.
References
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