Exsanguination from impact head trauma; the explanation for the "empty heart" sign

Twenty-four autopsied cases of lethal closed head trauma occurring sufficiently rapidly for the salient pathologic features to remain unobscured by medical intervention, and selected to exclude the possibility of exsanguination by other means, were analyzed for the presence or absence of exsanguination from basal skull fracture. The purpose of this study was to test the validity of the "Empty Heart" sign in head injuries, attributed by Hirsch and Zumwalt [C.S., Hirsch, R.E., Zumwalt, The "Empty Heart" sign. The American Journal of Forensic Medicine and Pathology 7 (2) (1986) 112-114] to a hypothetical neurologic reflex causing occult intra-corporeal sequestration of blood. The study revealed that the twelve cases with more severe injuries showed clear cut exsanguination (with "empty" hearts) due to basal skull fractures, while the twelve milder injury cases showed no signs of exsanguination, including the empty heart sign. No cases of cryptogenic empty heart were found. These findings demonstrate that the "empty heart" sign is merely an indication of exsanguination due to basilar skull fracture. The mechanism of exsanguination in these cases is discussed. The author's method for the determination of depleted blood volume at autopsy is described. The routine estimation of blood volume at autopsy and the inclusion of investigative data in forensic case assessment are recommended.