This case concerns a rare sudden cardiac death characterized by macroscopic and microscopic postmortem findings of hypertrophic cardiomyopathy and polyarteritis nodosa. A complete autopsy was carried out, and histological and histochemical methods were employed. The cause of death was acute multifocal ischemic myocitolitic damage caused by both myocardial structural alteration attributable to hypertrophic cardiomyopathy (widespread interstitial fibrosis and multifocal myocyte disarray) and coronary arteritis attributable to polyarteritis nodosa. This is the first case in which the cause of death was attributed to both diseases
