Dysplasie arythmogène du ventricule droit et mort subite : étude autopsique et histologique

Abstract

Arrhythmogenic right ventricular dysplasia (ARVD) is cardiomyopathy where normal myocardial tissue is replaced with fibrofatty tissue. Histological examination performed on myocardial biopsy or on autopsy samples are used to confirm the diagnosis. However, in many cases, the diagnosis cannot be made on a simple macroscopic and histological study and requires genetic analysis and molecular biology. In this work, we propose to describe the main macroscopic and histological findings of ARVD through the study of an autopsy series. We report 12 autopsy cases of sudden death in ARVD collected in the Department of Forensic Medicine of the University Hospital Fattouma Bourguiba Monastir (Tunisia) during a period of 20years. Microscopic examination was performed on 5microns thick histological sections. All slides were reviewed by two operators in a double blind (physician pathologist, pathologist) and in each, the percentage of adipose tissue, fibrosis and infarction in the right ventricle, left ventricle and interventricular septum, the presence or absence of inflammatory infiltrate, the presence or absence of signs of degeneration of myocytes were noticed. ARVD was found in 12 cases (1.8% of sudden cardiac death). The age ranged between 13 and 67years (mean age: 45.3years). The death occurred in half of the cases during exercise. Macroscopic examination of the RV showed the presence of a wall thinning (thickness<3mm) in 9 cases. Histological study highlight RV adipose infiltration in all cases with a percentage between 15% and 60%, fibrotic lesions were observed in only 9 cases with an average percentage of 10.25% and signs of degeneration of myocytes were noted in 10 cases. In concordance with what has been reported in the literature, there is still no consensus regarding the criteria to be adopted to pose with certainty the diagnosis of ARVD and the presence of adipose tissue remains the criterion more suggestive.