MR and CT imaging

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a rare cardiomyopathy characterized by fibro-fatty replacement of the right ventricle (RV), which leads to progressive RV failure and ventricular arrhythmias [1, 2]. The disease presents between the second and fifth decades of life either with symptoms of palpitations and/or syncope associated with ventricular tachycardia or with SCD. The exact prevalence of this condition is not known, but is estimated to be around 1 in 5,000. There is wide variation in the clinical presentation and course of ARVC/D [1-4] accounted for by the genetic heterogeneity of the disease. Mutations in genes encoding junctional plakoglobin are associated with palmoplantar keratoderma (Naxos disease) and woolly hair. Mutations in plakophilin, a desmosomal [5] protein, is associated with early presentation and higher incidence of ventricular arrhythmias [6]. Diagnosis of ARVC/D is often challenging, as the RV involvement in early ARVC/D can be focal with preserved global RV function. The diagnosis is based on a set of major and minor criteria proposed by the Task Force of cardiomyopathies in 1994 [7]. These criteria account for the electrical, anatomic and functional abnormalities that are a consequence of progressive fibro-fatty infiltration, which results in loss of RV myocytes. Structurally, this manifests as regional reduction in wall thickness and wall hypertrophy secondary to fat infiltration. Focal or global contraction abnormalities, chamber enlargement, enlarged RV outflow tract, and RV aneurysms have been described.