Biological rhythms of fatal myocardial infarction in Greece: an autopsy study

Abstract

Background Biological rhythms, acting as an endogenous clock, prepare and assist the organism to function optimally during predictable seasonal and daily cycles. Many elements of the cardiovascular system exhibit specific rhythmical patterns. Besides genetic mechanisms, external stimuli may alter biological rhythms. Methods The aim of this study was to investigate the patterns of biological rhythms in patients who suffered a fatal myocardial Infarction (MI), ascertained by macroscopical or histopathological examination. Cases of fatal MI examined during the time 2010–2017 were included in our study sample (827 cases in total). Medical History was also obtained for each case. The assessment of seasonal variation of fatal MI was accomplished by employing three different methods, Rayleigh Uniformity Test, X2 Goodness-of-fit test and Edward’s Seasonality Test. Statistical significance was defined as a 2-sided p value of <0.05. Results Regarding the distribution of total cases, fatal MIs onset occurs more often during winter, with higher incidence in December and January. The weekly distribution of cases seems uniform. The circadian pattern presents higher frequencies of fatal MIs between 08:00 and 12:00 with the acrophase between 11:00 and 12:00. Further analysis was conducted separately, depending on the method of time-of-death reporting. Conclusions Taking under consideration the variation of the occurrence of MI related deaths, in accordance with the respective biological rhythms, public health policies more suitable to the individual requirements of every country's population may be adopted.