Mort subite d’origine cardiaque au nord de la Tunisie : variation circadienne, hebdomadaire et saisonnière

Summary 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.