Histopathological Characteristics of Human Cardiac Tissues in Accidental Hypothermia Using Conventional Staining Techniques

We examined characteristics or cardiac cell damage in the myocardium obtained from individuals who died due to hypothermia or coldwater immersion. We could find four kinds of histological changes in the heart tissues obtained from hypothermia and coldwater immersion death. Although the red or orange colored cardiac cells, vacuolar cardiac cells and contraction band of the cardiac cells were observed in the heart from individuals with cardiac infarction, the frequency and intensity of the finding was remarkable in hypothermic death, and closely adhered cardiac cells were detected only in the myocardium from hypothermic or coldwater immersion death. We additionally discussed the mechanisms of development of these findings by comparing the results obtained in this examination with some reports in the literatures. houses, and one child who died from abuse. The other 10 victims were found their death inside or around their houses and no remarkable injury was found on their body except the erythema on their knees in some cases. The eliminated three cases in which the victims showed prolonged postmortem interval were not suitable for the histological research. We also examined the myocardium from three cases as the comparative cases in which individuals died from drowning after immersion in a lake or canals in winter, that is, a young man was forced to go into a lake in winter, and in the last two cases young woman and man separately fell into canals with a motorcycle or a bicycle. In the last two cases, climbing traces were remained on the canal banks. Additionally we used the myocardium from traffic accidents cases with or without brain and/or cardiac injury, and cardiac infarction cases with bleeding and leukocyte infiltration as the control cases. Four parts of the heart, that is, crosscutting tissues of left and right ventricle and septum, and longitudinal section of septum from each individual were obtained and fixed in formalin. The sections with 3 μm thickness of paraffin embedded myocardium were prepared for HE and Azan staining. These staining were usually performed at our department for postmortem investigation. We used microscope apparatus from Nikon (EcliPSE 80i attaching HPxw4300 workstation) for making pictures of the cardiac tissues by HE and Azan, and from Keyence (BioRevo BZ-9000 attaching HPxw4300 workstation) for 3D analysis of extent of the orange colored cardiac cells in 25 serial sections by Azan stain.