ARVD/C is a heart disease affecting the right ventricle, resulting in fibrofatty replacement of the myocardium. These patients are at risk of developing ventricular arrhythmias possibly leading to syncope or sudden death. Many of these patients have a genetic predisposition, and it seems as athletes are at a higher risk of developing cardiac arrhythmias. The diagnosis is based on clinical examination, history, radiological and genetic investigations.This is a rare disease with major impact of those affected. The disease in itself is not curable, but there are effective symptomatic treatments. These patients should be referred to a cardiology specialist centre with competance on this rare condition. The knowlegde of ARVD/C is minor amongst most Gps, specialists in internal medicine and even many cardiologist. We can assume that the number of affected patients is higher than known today.In this project report we present an overview of present knowledge on ARVD/C. We have also done a retrospective study of the ARVD/C followed up at Ullevaal University Hospital in Oslo.There is so far no existing register of the number being treated. Another problem is that there is no systematic use of international criterias at Ullevaal. Because of this, the diagnosis has been based on clinical experience and there has been inadequate documentation of findings.It has been developed genetic tests which are now availeble for clinical use. We will offer these tests to the patients we have identified through our search in the electronical recordings at Ullevaal. This work will be completed during 2008.