| Abstract: | The objective of this study was to evaluate the epidemiological characteristics of sudden death (S.D.), with particular reference to the presence of chronobiological rhythms. One hundred eighty-five fatal events were observed during one solar year at the Emergency Department of a northern Italian town. Twenty-three cases were due to accidents or violence, while the remaining 162 corresponded to the operative definition of S.D. we adopted. Investigation by autopsy permitted to recognize that 36% of total deaths were due to cardiovascular diseases (in 2/3 of the cases secondary to ischemic heart diseases). A significant circadian periodicity was observed in S.D. (p=0.01, with two peaks, at 9.26 a.m. and 9.26 p.m.) and also a circannual rhythm, peaking in late autumnDearly winter (p=0.036). The latter was particularly evident in elderly people. A relationship with cardiovascular event rate (of which S.D. recalls the circadian periodicity) is a plausible explanation, while the frequent occurrence of respiratory distress during winter may be at least partly responsible for the high incidence of unexpected deaths seen in this period of the year. |
