Sudden Death May Show a Circadian Time of Risk Depending on Its Anatomo-clinical Causes and Age

The aim of this study was to determine whether the time of occurrence of sudden death exhibits a circadian rhythm depending on its different anatomoclinical causes. A longitudinal prospective investigation of 610 nonhospitalized subjects who died suddenly in the Emergency Room of Ferrara Hospital between January 1983 and December 1990 was conducted. All subjects underwent autopsy. Sudden death was classified on the basis of the following pathological causes; acute myocardial infarction, acute myocardial failure, intracerebral hemorrhage, rupture of aortic aneurysm, pulmonary embolism, and clinical causes, i.e., arrhythmia and circulatory failure. The investigated cases were stratified into 2 groups according to age; Group A=age <70 years (n=301, 49.3%), and Group B=age =70 (n=309, 51.7%). The assessment of circadian rhythmicity was performed utilizing the single cosinor method. The results by cosinor analysis found a circadian rhythmicity for cases of sudden death (peak at 14.04, n=610...