Utility of myocardial fibrosis and fatty infiltration detected by cardiac magnetic resonance imaging in the diagnosis of arrhythmogenic right ventricular dysplasia--a single centre experience.

INTRODUCTION: Cardiac magnetic resonance imaging (CMR) has evolved as a major diagnostic tool to evaluate arrhythmogenic right ventricular dysplasia (ARVD). However, there is a lack of consensus in the interpretation of findings such as fatty infiltration or myocardial fibrosis. We examined the diagnostic utility of these two features in the diagnosis of ARVD.
METHODS: We performed fast imaging employing steady-state acquisition cine imaging, T(1)-weighted black blood imaging with and without fat suppression and post-contrast delayed enhancement on a 1.5-T scanner to evaluate ventricular function and morphology, fatty infiltration and regional myocardial fibrosis in 52 subjects with suspected ARVD.
RESULTS: Eight subjects met the international diagnostic criteria for ARVD. Right ventricle (RV) delayed hyper-enhancement was found in 7 of 8 (88%) ARVD subjects compared to 6 of 44 (14%) subjects without ARVD (p<0.001). Fatty infiltration was only identified in 1 ARVD patient, and 1 non-ARVD patient. On multiple logistic regression analysis RV enhancement remained an independent predictor for the diagnosis of ARVD (p<0.05).
CONCLUSION: RV delayed enhancement is common in patients with ARVD, whereas detection of fatty infiltration of the right ventricle was rare in our patient population. The inclusion of RV fibrosis on CMR as a feature of ARVD may improve the diagnostic accuracy of this condition.