[Relation entre la température ambiante, l'humidité et la mort subite cardiaque au nord de la Tunisie]. / Relationship between ambient temperature, humidity and sudden cardiac death in northern Tunisia.

BACKGROUND: Several studies have suggested a relationship between weather parameters and the occurrence of sudden cardiac death. AIM: The aim of this work was to study the impact of changes in temperature and humidity level on the occurrence of sudden cardiac death in the north of Tunisia. METHODS: it's an autopsic study that included all victims of sudden cardiac death occurring in northern Tunisia between October 2010 and September 2012. The minimum, maximum and average of daily temperatures and humidity during the study period were recorded and compared with the monthly variation in the occurrence of sudden death. RESULTS: The study population included 392 men and 108 women with a mean age of 52.2 + / - 15.8 years.The highest rate of sudden death (37%) was observed at ambient temperatures below 15 degrees and only 4.2% of deaths occurred at temperatures above 30 degrees ambient temperatures (p <0.001). Among the population aged over 60 years, the highest mortality rate (47.3%) were recorded at temperatures below 15 degrees, while 35.5% of young patients under 40 years died during periods with temperatures between 20 and 30 degrees and 56.8% of deaths occurred in the humidity levels between 60 and 78% . CONCLUSION: In the north of Tunisia where the climate is temperate, a temperature drop below 15 degrees was significantly associated with a sudden cardiac death. This excess winter cardiac mortality was more pronounced in the elderly.

[Diurnal, weekly and seasonal variation of sudden cardiac death in northern Tunisia]. / Mort subite d'origine cardiaque au nord de la Tunisie : variation circadienne, hebdomadaire et saisonnière.

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.