[Diurnal, weekly and seasonal variation of sudden cardiac death in northern Tunisia].

Background: Several studies have reported a circadian variation in the occurrence of sudden cardiac death.

Aim: To analyze the circadian, weekly and seasonal variations of sudden cardiac death occurring in northern Tunisia.

Methods: We prospectively collected epidemiological and autopsic data of victims of sudden cardiac death occurring in the northern governorates of Tunisia between October 2010 and September 2012.

Results: The study population included 392 men and 108 women with a mean age of 52.3±15.8 years. Physical inactivity and smoking were the most common risk factors, they accounted for 76.4% and 57.9% respectively. Family history of sudden death was identified in 9.8% of victims. The vast majority of deaths occurred in a public place (41.4%) or at home (36.6%). Ischemic heart disease was the most frequent causes of death (269 cases). Sudden cardiac death was homogeneously distributed over the day. A maximum of events occurred on Sundays (17.8%) and a minimum on Mondays (11.4%), we also recorded an excess cardiac mortality in winter with a peak in December and a nadir in September (13% vs. 4.4% P=0.0001).

Conclusions: In northern Tunisia, under Mediterranean climate, a winter excess cardiac mortality was found. Sudden cardiac death was homogeneously distributed over the day, however, an excess of mortality was recorded over the weekend with a nadir on Monday.