Objective: To evaluate the diagnostic value of magnetic resonance imaging (MRI) for arrhythmogenic right ventricular cardiomyopathy (ARVC).
Methods: MRI was performed in 27 (male 21, mean age: 37.4 y, ranging from 15 - 67 y) clinically diagnosed ARVC patients according to the 1994 ARVC diagnosis criteria of WHO from Oct. 2004 to Jun. 2006. Heart chamber size, fat infiltration, local or global ventricular function, myocardium perfusion of contrast first pass and late enhancement were examined.
Results: Fat infiltration was found in 24 (88.89%), trabecular disarray in 17 (62.96%), significant dilated right ventricle outlet (RVOT) in 18 (66.67%), dilated RV apex in 14 (51.85%), dilated RV free wall and posterior wall in 18 (66.67%) and right atrium enlargement in 11 (40.74%) patients. Local RV dysfunction was found in 18.52% (5/27), global RV dysfunction in 70.37% (19/27) of patients with mean RV ejection fraction (EF) of 35%. Left ventricle was affected in 40.74% (11/27) of patients. Perfusion defects were found in only 10.52% (2/19) of patients. Positive late enhancement of myocardium were found in 36.84% (7/19) of patients and affecting mainly the wall of RVOT and the free wall associated with lateral wall enhancement of LV. Five patients received heart transplantation and histology on transplanted hearts confirmed the MRI findings.
Conclusion: "One-stop-shop" MRI scanning can be used for the diagnosis of ARVC. While for some ARVC cases with dominant abnormality in LV, it is difficult for MRI to differentiate ARVC from dilated cardiomyopathy or coronary heart disease. We found fibrosis of lateral wall of LV can be a characteristic sign of ARVC.