Familial isolated arrhythmogenic right ventricular dysplasia (ARVC) is the familial autosomal dominant form of ARVC, a heart muscle disease characterized by life-threatening ventricular arrhythmias with left bundle branch block configuration that may manifest with palpitations, ventricular tachycardia, syncope and sudden fatal attacks, and that is due to dystrophy and fibro-fatty replacement of the right ventricular myocardium that may lead to right ventricular aneurysms. The disease is familial isolated arrhythmogenic right ventricular dysplasia (MONDO_0016342, a Monarch Disease Ontology entry). Also known as: familial isolated ARVC, familial isolated ARVD, familial isolated arrhythmogenic right ventricular cardiomyopathy, familial isolated arrhythmogenic ventricular cardiomyopathy, familial isolated arrhythmogenic ventricular dysplasia.