Brugada Syndrome and Arrhythmogenic Right Ventricular Cardiomyopathy

Abstract

Brugada syndrome (BrS) and arrhythmogenic right ventricular cardiomyopathy (ARVC) are inherited cardiac disorders with distinct electrocardiographic findings and lethal ventricular arrhythmias. BrS is primarily associated with loss-of-function SCN5A variants, which cause repolarization abnormalities such as coved-type ST elevation based on transmural action potential gradient in the right ventricular outflow tract (RVOT). Fibrosis on the epicardial side of RVOT, as well as abnormalities of the gap junction provide the arrhythmogenic substrate and cause depolarization abnormalities. BrS typically appears in middle age and is 8–10 times more common in males. Although testosterone is thought to cause male predominance, estrogen may act as a protective factor in female BrS. ARVC is predominantly induced by abnormalities in desmosome-related genes, which disrupt intercellular adhesion and the Wnt/β-catenin pathway, leading to the replacement of cardiomyocytes with fibro-fatty tissues. This abnormality causes electrocardiographic findings like ε-waves and negative T waves in the right precordial leads. ARVC with right ventricular involvement is diagnosed using revised Task Force criteria, whereas arrhythmogenic cardiomyopathy (ACM) with left ventricular or biventricular involvement is diagnosed using Padua criteria. BrS and ARVC are uncommon in children, but the frequency of lethal ventricular arrhythmias is higher than in adult patients. Additional research is required to determine risk stratification and treatment options for pediatric patients.