Histological examination as one of the main methods that allow to substantiate conclusions of forensic medical examination

We present the case of postmortem diagnosis of rare in forensic medical practice disease — of arrhythmogenic dysplasia and the analysis of morphological and microscopi manifestations of the disease. Arrhythmogenic right ventricular dysplasia (ARVD) belongs to primary cardiomyopathy. This pathology of unclear etiology is usually an isolated impairment of the right ventricle (RV), often running in the family, characterized by fatty or fibrofatty infiltration of ventricular myocardium accompanied by heart rhythm disorders (HRD) of the ventricles of various severity, including ventricular fibrillation. Prevalence of ARVD has been studied not enough due to the fact that the onset of the disease is often asymptomatic. In 80% of cases it is revealed under the age of 40, more frequently in males. Some authors consider ARVD to be the cause of sudden cardiac death (SCD) in 26% of children and adolescents. SCD may be the first and the only manifestation of ARVD, particularly in young people and sportsmen. According to the data by the American authors, ARVD is diagnosed posthumously approximately in 5% of SCD cases in people younger than 65 years of age and in 3-4% cases of death in young sportsmen during competitions. Opinions as to pathogenesis of the disease come to two theories: ARVD is a congenital anomaly of development of RV myocardium called dysplasia. The onset of tachycardia may be postponed for many years until RV is considerably enlarged and the size of arrhythmogenic substrate is big enough to cause persistent ventricular tachyarrhythmia (VT). The second theory connects the onset of RV dysplasia with metabolic disturbances involving RV and causing progressing myocyte replacement (apoptosis). Islets of fibrofatty tissue revealed in ARVD form arrhythmogenic substrate carrying conditions for development of reentry underlying malignant VT.