Sudden death from pulmonary thromboembolism: chronobiological aspects.

The aim of this study was to determine whether sudden cardiac death from pulmonary embolism exhibits any chronobiological rhythm. Five hundred and seven consecutive subjects dying suddenly outside of hospital and brought into our Emergency Department from January 1983 to December 1989 were studied. The time and date of event were accurately recorded. All subjects underwent autopsy and 48 of them were found to have died of pulmonary embolism (23 males, mean age 73.9 +/- 8 years and 25 females, mean age 76 +/- 12 years). All data were analysed by means of single cosinor[19,20]. In the subjects with pulmonary emboli both a circadian and a circannual rhythmicity were found, with a significant acrophase respectively in the morning (h.min. 11.46, P = 0.003) and in winter (-19.3, P = 0.009).