A case of sudden death in a young boy affected by hypertrophic cardiomyopathy

Introduction: hypertrophic cardiomiopathy is a genetic-based pathology, characterised by a relevant homogeneous thickening of heart walls. Its incidence is still unknown, while its aetiology seems to depend on multiple mutations of 9 different genes codificating for sarcomeric proteins (myosine), whose structural integrity is essential for the physiologic work of the cardiac muscle. Hypertrophic cardiomiopathy is familial in half of patients and its transmission pattern is autosomal dominant with variable expression. Remaining cases are considered sporadic. Methods: it is reported a case of a 16 years old boy, who suddenly fell down and died at a bus stop in Milan, after an afternoon spent out with friends. He always had good health before that day. There was no evidence that he had assumed drugs that day or that he was drug addicted. The autopsy was undertaken in Milan City Morgue. Results: at the autopsy a relevant cardiac hypertrophy was found: the heart had a rounded shape and it was larger and heavier than normal, with evident thickening of heart walls (especially left ventricular walls and I-V septum, the latter badly influencing the blood outflow from left ventricle). Multiple cardiac samples were then analysed histologically: myocite hypertrophy, myocite disarray, patchy interstitial fibrosis and thickening of coronaric arterioles walls were found. Toxicological tests were negative. Conclusions: the pathologic findings (coming from autopsy and from microscopic examination) are pathognomonic for congenital hypertrophic cardiomiopathy. This disease was considered responsible for the young boy’s sudden death. The young age of the victim and the total lack of previous symptoms or signs (in spite of the presence of an overt pattern of advanced concentrical left ventricular hypertrophy) make this case unusual.