Arrhythmogenic right ventricular cardiomyopathy with an initial manifestation of severe left ventricular impairment and normal contraction of the right ventricle

A case of arrhythmogenic right ventricular cardiomyopathy (ARVC) with an in itial manifestation of severe impairment of the left ventricle (LV) and nor mal contraction of the right ventricle (RV) is presented. A 43-year-old man was admitted to hospital because of congestive heart failure following a c ommon cold. The LV function was diffusely and severely hypokinetic. Coronar y arteriogram revealed normal vessels. An endomyocardial biopsy specimen ob tained from the RV septum revealed mild infiltration of lymphocytes with fo cal myocytes necrosis and so healing myocarditis was suspected. The specime n did not include any fatty replacement of myocytes. Since then, the patien t suffered from recurrent congestive heart failure as well as nonsustained ventricular tachycardia and required frequent hospitalization. Progressive impairment, dilation, and thinning of both ventricles were observed on seri al echocardiographic examinations. Although the RV gradually enlarged and b ecame impaired, severe dilatation and impairment of the LV has always been predominant in the patient's clinical course. After medical follow-up for 1 0 years, he died suddenly of ventricular fibrillation and pump failure. The autopsy revealed extensive fibrofatty replacement of myocytes in both the ventricles, extending from the outer layer to the inner layer of myocardium in the RV and to the middle layer in the LV. These features were compatibl e with arrhythmogenic right ventricular cardiomyopathy or perimyocarditis, although only the right-sided bundle of the interventricular septum was com pletely replaced by fatty tissue, which can not be explained as a sequel of perimyocarditis. Moreover, apoptosis was present in the myocyte nuclei of the myocardial layers bordering the area of fatty replacement. Therefore, m yocarditis may have triggered or accelerated the process of apoptosis leadi ng to ARVC.