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Imaging in Arrhythmogenic Right Ventricular Dysplasia (ARVD)

Practice Essentials

Arrhythmogenic right ventricular dysplasia (ARVD) is an unusual, often familial, condition characterized by the replacement of myocardial tissue by fat and fibrous tissue (as demonstrated in the image below). ARVD has a wide spectrum of clinical presentations, including mechanical dysfunction and various forms of ventricular arrhythmias. It is a cause of sudden death, mostly in young people and athletes.

Anatomic changes of the right ventricle consist of mild to severe global dilatation, aneurysms, and segmental hypokinesia. Sites of involvement of the right ventricle are found in the triangle of dysplasia, namely, the right ventricular outflow tract, the apex, and the infundibulum. Mutations have been identified in 5 desmosomal genes.

Electrocardiographically gated T1-weighted image s

Electrocardiographically gated T1-weighted image shows arrhythmogenic right ventricular dysplasia (ARVD) with prominent epicardial fat in the right ventricular outflow tract.

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Preferred examination

The recognition of mild, forme fruste, and localized forms of ARVD remains a clinical challenge. Diagnosing ARVD in patients with minimal right ventricular abnormalities is difficult to accomplish using echocardiography, ultrafast computed tomography (CT) scanning, radionuclide angiography, multidetector computed tomography, and contrast-enhanced angiography.

Magnetic resonance imaging (MRI) is a promising technique for showing the anatomy and function of the right ventricle, as well as for characterizing the composition of the right ventricle’s wall, especially with regard to adipose tissue. However, the diagnostic sensitivity and specificity of MRI remain to be defined, because the quality of images detected is observer dependent. Signal intensity suggesting the presence of fat in the right ventricle may be related to a latent form of the disease or to the dissociation of myocardial tissue by fat. Therefore, only the combination of MRI signs, including the size, function, and fat content in the free wall, is necessary to support the diagnosis.

MRI has the advantage of offering methods that specifically eliminate or selectively include signal from only fat, which resonates at a different frequency than that of tissue or water. For example, a spatiospectral pulse sequence can be used to selectively image fat by using a gradient-echo technique, and a triple-inversion recovery sequence can be applied to nullify signals from fat. However, wall motion, gating abnormalities, or other artifacts can produce false-positive results, which must be eliminated by means of inspection and/or the acquisition of confirmatory views.

In some cases, endomyocardial biopsy may be necessary to confirm the diagnosis.

In 2010, a Task Force proposed revisions to the 1994 International Task Force criteria for the clinical diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D), which facilitated recognition and interpretation of the frequently nonspecific clinical features of ARVC/D. The Task Force elaborated on newer imaging techniques, such as contrast-enhanced echocardiography, 3-dimensional echocardiography, cardiovascular magnetic resonance with late enhancement, and electroanatomic voltage mapping.

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