Arrhythmogenic right ventricular cardiomyopathy (ARVC): cardiovascular magnetic resonance update

Abstract

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is one of the most arrhythmogenic forms of inherited cardiomyopathy and a frequent cause of sudden death in the young. Affected individuals typically present between the second and fourth decade of life with arrhythmias coming from the right ventricle. Pathogenic mutations in genes encoding the cardiac desmosome can be found in approximately 60% of index patients, leading to our current perception of ARVC as a desmosomal disease. Although ARVC is known to preferentially affect the right ventricle, early and/or predominant left ventricular involvement is increasingly recognized. Diagnosis is made by combining multiple sources of diagnostic information as prescribed by the "Task Force" criteria. Recent research suggests that electrical abnormalities precede structural changes in ARVC. Cardiovascular Magnetic Resonance (CMR) is an ideal technique in ARVC workup, as it provides comprehensive information on cardiac morphology, function, and tissue characterization in a single investigation. Prevention of sudden cardiac death using implantable cardioverter-defibrillators is the most important management consideration. This purpose of this paper is to provide an updated review of our understanding of the genetics, diagnosis, current state-of-the-art CMR acquisition and analysis, and management of patients with ARVC.

Figure 1

Four-chamber (top panels) and short-axis (bottom panels) bright blood images in an ARVC subject with predominant right ventricular abnormalities. End-diastolic images are shown in the left panels, end-systolic images in the right panels. Note subtricuspid dyskinesia in the end-systolic four-chamber image (arrow), and right ventricular free wall aneurysms (i.e. both systolic and diastolic bulging) in the short-axis image (arrows).

Figure 2

Regional contraction abnormality in the subtricuspid region. End diastolic (left) and end systolic image (right) show the so-called “accordion sign” in an ARVC mutation carrier. Regional dyssynchronous contraction in the subtricuspid region is a readily recognized qualitative pattern of abnormal RV contraction.

Figure 3

Horizontal long-axis (top panels) bright blood and late gadolinium enhancement images (bottom panels) in an ARVC subject with predominant left ventricular abnormalities. Note a dilated left ventricle in the bright blood images. Late enhancement is observed in a mid-myocardial pattern in the basal septum and basal lateral wall (arrows, bottom panels).

Figure 4

Horizontal long-axis bright blood image in an ARVC patient revealing left ventricular lateral wall fatty infiltration with myocardial wall thinning (arrowhead).

Figure 5

Right ventricular late gadolinium enhancement in ARVC. The short axis image (left) shows LGE in the RV as well as the LV (black arrows). The lateral wall of the LV shows thinning due to fatty replacement that was confirmed on T1-weighted images. The long axis view (right) shows diffuse LGE involving the free wall of the RV.

Figure 6

Butterfly apex as a normal variation. Stack of horizontal long axis views from inferior (image 1) to superior (image 4) in a control subject. Note the appearance of a butterfly apex on inferior views (arrows in images 1–3). This appearance is not seen on the more superior view (panel 4).

Figure 7

Misdiagnosis of ARVC - Axial and short-axis bright blood images in a control subject. Note the “tethering” of the mid right ventricular free wall to the anterior chest wall (arrows), giving the right ventricle a dyskinetic appearance.