ARVC

Arrhythmogenic right ventricular cardiomyopathy (ARVC), also called ARVC/d, is a hereditary cardiomyopathy characterized by progressive replacement of right ventricular myocardium with fibrous and fatty tissue. This structural change creates a substrate for ventricular arrhythmias and can lead to sudden cardiac death, especially in young people and athletes. The condition was historically referred to as arrhythmogenic right ventricular dysplasia, but current terminology emphasizes the disease process rather than dysplasia.

Most cases are autosomal dominant with incomplete penetrance and variable expressivity. Mutations in desmosomal genes are the most common causes, including PKP2, DSP, DSC2, DSG2 and JUP, among others. Non-desmosomal gene mutations have been described as well. Genetic testing and family screening are often recommended when a pathogenic variant is identified.

Patients may present with palpitations, lightheadedness, syncope, or no symptoms until a malignant arrhythmia occurs. Ventricular tachycardia with a left bundle branch block pattern is typical. Electrocardiography may show epsilon waves and T-wave inversions in the right precordial leads (V1–V3). Imaging demonstrates regional right ventricular dilation and wall motion abnormalities; cardiac MRI can reveal fatty or fibrous replacement. Diagnosis uses criteria that combine structural, histological, electrocardiographic, arrhythmic, genetic, and family history data. Endomyocardial biopsy has limited sensitivity due to sampling error.

Management aims to prevent sudden cardiac death and control arrhythmias. Athletes are advised to limit strenuous exercise. Pharmacologic therapy includes beta-blockers and antiarrhythmic agents such as amiodarone; catheter ablation may reduce arrhythmia burden in selected cases. An implantable cardioverter-defibrillator (ICD) is recommended for high-risk individuals, such as those with survived cardiac arrest or sustained VT. Family members should undergo clinical evaluation and genetic testing when a pathogenic variant is identified.

Prognosis varies with disease extent and arrhythmic risk. With ICD therapy and activity modification, outcomes improve, but ARVC remains a leading cause of sudden death in young people. Prevalence estimates are low, typically around 1 in 1,000 to 1 in 5,000, with higher apparent rates in athletic populations.