Arrhythmogenic cardiomyopathy (ARVC) is a disease of the heart muscle. ARVC is a rare genetic disease. Normal heart muscle breaks down, being replaced with fatty fibrous tissue, mainly in the right ventricle. These changes may also happen in the left ventricle. Abnormal electrical circuits in the heart muscle may develop, leading to irregular and possibly dangerous heart rhythms (arrhythmias). The heart also becomes weaker over time. This can lead to heart failure.