Arrhythmogenic right ventricular cardiomyopathy. Contribution of cardiac magnetic resonance imaging to the diagnosis

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited disease of the heart muscle, mostly due to genetically defective desmosomal proteins. The disease is characterized by fibrofatty replacement leading to ventricular arrhythmias and sudden death in young people and athletes. There is no single clinical gold standard examination for making a definitive diagnosis. The diagnosis is based on multiple parameters, including: (1) global or regional dysfunction and structural alteration of the right ventricle demonstrated on imaging; (2) tissue characterization by endomyocardial biopsy; (3) repolarization and (4) depolarization electrocardiographic abnormalities; (5) arrhythmias; and (6) family history. The so-called phenocopies must be included in the differential diagnosis, always taking into account that there is no single criterion sufficiently specific for a reliable diagnosis of ARVC. Contrast-enhanced cardiac magnetic resonance imaging (CE-CMR) is not yet included in the revised diagnostic criteria, although this is the only imaging modality able to depict fibrosis as late gadolinium enhancement (LGE) deposition. This review analyzes the role of CMR imaging in the diagnostic work-up of ARVC. The lack of specific diagnostic criteria contributes to the under-recognition of the nonclassic variants of ARVC, i.e., dominant or isolated left ventricular disease.