Arrhythmogenic right ventricular cardiomyopathy: an overview and update

Arrhythmogenic right ventricular cardiomyopathy consists in partial or total progressive replacement of cardiac muscle fibers with a fibro-adipose tissue. This is a hereditary disease with an autosomal dominant inheritance with incomplete penetrance and variable expressivity, except two autosomal recessive syndromes. The most frequent abnormal proteins are that of desmosomal intercellular junctions, such as junctional plakoglobin, plakophilin-2, desmoplakin, desmoglein-2, and desmocollin-2, although other types of non-desmosomal components may be also involved. Desmosomal disorders result in myocardial fibers necrosis and their progressive replacement with fibro-adipose tissue. The morphological modifications are usually beginning in the subepicardial layer and develop towards the endocardium, being associated with the ventricular wall degeneration, thinning, and progressive increase of the amount of adipose tissue. The average age of clinical manifestations onset is around 30-40 years old, with ventricular arrhythmia and high risk of sudden death. Currently, the diagnosis is based on the 2010 Task Force Diagnostic criteria. The current review presents an overview on traditional knowledge about this disease, adding updated information regarding molecular and genetic data. The knowledge of this disease is important for medical practice as a possible cause of arrhythmia and sudden death and its prognosis might be improved by appropiate genetic testing as family screening.