Arrhythmogenic right ventricular dysplasia (ARVD) is a myocardial disease, often familial, that is characterised pathologically by fibrofatty replacement of the right ventricular myocardium, and clinically by ventricular arrhythmias of right ventricular origin which may lead to sudden death, mostly in young people and athletes. The term "dysplasia" was originally used to describe an entity that was considered to be the result of a developmental defect of the right ventricular myocardium.