Arrhythmogenic right ventricular dysplasia/cardiomyopathy: new avenues for diagnosis and treatment.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is a heart muscle disorder of unknown course that is characterised pathologically by fatty or fibrofatty replacement of the right ventricular myocardium and electrical instability. Clinical manifestations include structural and functional malformations of the right ventricle, electrocardiographic abnormalities, and presentation of ventricular tachycardias with left bundle branch pattern or sudden death. The disease is often familial with an autosomal inheritance. In addition to right ventricular dilatation, right ventricular aneurysms are typical deformities of ARVD/C and they are distributed in the so-called 'triangle of dysplasia', i.e. the right ventricular outflow tract, apex and infundibulum. Ventricular aneurysms at these sites can be considered highly suggestive for ARVD/C. Another typical hallmark of ARVD/C is fatty or fibrofatty infiltration of the right ventricular free wall with potential extension to the left ventricle. These functional and morphological characteristics are relevant to clinical imaging investigations such as contrast angiography, echocardiography, radionuclide angiography, ultrafast-computed tomography and magnetic resonance (MR) imaging. Among these techniques, MR imaging allows the most comprehensive assessment of the heart, in particular because it provides functional and flow-dynamic information in addition to anatomic images. Furthermore, MR imaging offers the specific advantage of visualising adipose infiltration as a bright signal of the right ventricular myocardium. Non-pharmacological treatment by radio-frequency ablation and implantable defibrillators will play an increasing role in the treatment of patients with ARVD/C, especially in case of drug ineffectivity. Despite new diagnostic and therapeutic approaches in ARVD/C, there remain many unanswered issues since the current guidelines present criteria that are highly specific but lack sensitivity. Therefore, optimal assessment of diagnostic criteria would require a prospective evaluation from a large population obtained by an international registry.