Echocardiography in arrhythmogenic right ventricular dysplasia/cardiomyopathy: Can the technology survive in the era of cardiac magnetic resonance imaging?

Arrhythmogenic right ventricular dysplasia/ /cardiomyopathy (ARVD/C) is a genetically determined heart muscle disorder that is characterized pathologically by fibrofatty replacement of the right ventricular (RV) myocardium. The clinical diagnosis of ARVD/C is complex, since there is no single diagnostic “gold standard”. The diagnosis is based on major and minor criteria that have been modified and take into account heart structure and function, family history, genetic mutations, histology, ventricular arrhythmias, and electrocardiographic abnormalities [1]. Diagnostic imaging criteria include regional RV wall motion abnormalities in combination with RV dilatation or global RV systolic dysfunction [1]. Conventional echocardiography is capable of detecting these changes in the RV, consisting of visual regional wall motion analyses, outflow tract dimensions and RV-fractional area change, and remains part of the current diagnostic Task Force criteria [1]. However, a comprehensive and accurate evaluation of the RV by echocardiography is technically challenging due to the retrosternal position and complex geometry of the RV. Cardiac magnetic resonance (CMR) imaging has revolutionized the diagnostic accuracy for ARVD/C and found to be of superior value compared to conventional echocardiography [2]. Pathologies causing RV volume overload such as intracardiac shunts (e.g. atrial septal defects, anomalous pulmonary venous drainage) can be misinterpreted as possible ARVD/C on standard echocardiography [3], and we often depend on CMR for a more definitive diagnosis. Although the role of echocardiography versus CMR in ARVD/C is subject to debate, it still remains the initial screening modality that can provide the first clue towards the diagnosis. In addition, CMR is often not feasible for the periodic follow-up of ARVD/C due to the high rate of implantable cardioverter-defibrillator (ICD) implantation and the relative high cost. There have been recent advances in echocardiography with the availability of novel techniques such as 3 dimensional right ventricular (3D-RV) imaging and tissue deformation imaging. These methods could improve the diagnostic and prognostic performance of echocardiography in these patients. In this issue of ”Cardiology Journal”, Mast et al. [4] describe the current and future role of both conventional and new echocardiographic parameters in ARVD/C with respect to diagnosis and follow-up. The authors provide an ARVD/C focused echocardiographic protocol which is currently in use in their institution. They discuss 3D-RV imaging which enables more accurate RV volumetric measurements compared to conventional echocardiography [5]. With the implementation of 3D-echocardiography, subtle global RV systolic