Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia: Mechanisms and Management

Abstract

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a primary cardiac myocytes disorder that predominantly affects the right ventricle. It is mainly inherited as autosomal dominant with variable expressivity; it also has been recognized as one of the major genetic causes of sudden cardiac death in the young and in athletes. The desmosomal protein is the most commonly affected structure and around 60\% of diagnosed cases have an identified genetic mutation. ARVC is characterized histologically by the replacement of cardiomyocytes with fibro-fatty tissue that is progressive over time. The most commonly involved sites in the heart are right ventricle inflow tract, right ventricular outflow tract and posterolateral wall of the left ventricle. New diagnostic criteria have increased the sensitivity and specificity for ARVC/D. These include imaging evidence of RV regional wall motion abnormalities and RV dilatation using echocardiography, cardiac magnetic resonance imaging and angiography. Other diagnostic criteria include fibrous replacement of the RV-free wall on biopsy, repolarization and conduction abnormalities on the electrocardiogram as well as ventricular tachyarrhythmias and significant family history. Management involves assessing for implantable-cardioverter implantation, pharmacological therapy for prevention of ventricular arrhythmias and treatment of any ventricular dysfunction. Patients with ARVC/D who are engaged in strenuous/endurance/competitive physical activity have 2-5-fold increased risk of sudden cardiac death and restriction from competitive/endurance sports is important. Family screening is important to identify asymptomatic patients.