Seasonal variation in sudden death in the Negev Desert region of Israel

Background: Previous studies have documented an increased incidence of card iac mortality and sudden death during winter months. Objectives: To evaluate seasonal variation in sudden death in a hot climate such as the desert region of southern Israel. Methods: We analyzed the files of 243 consecutive patients treated for out- of-hospital sudden death by the Beer Sheva Mobile Intensive Care Unit durin g 1989-90. Daily, monthly and seasonal incidence of sudden death was correl ated with meteorological data, including temperature, heat stress, relative humidity and barometric pressure. Results: The seasonal distribution of sudden death was 23% in spring, 21% i n summer, 25% in autumn and 31% in winter (not significant). In patients wi th known heart disease there were more episodes of sudden death in cold wea ther (<15.4 degrees C) than hot (>34.2 degrees C) (16 vs. 3, P<0.05). Resus citation was less successful in cold compared with hot weather (28 vs. 11, P<0.05). Of patients older than 65 years, 11 sustained sudden death when he at stress was below 12.4 degrees C compared to 2 patients when heat stress was above 27.5 degrees C (P=0.05). Conclusion: Despite the warm desert climate, there were more cases of sudde n death in older patients and in those with known heart disease during the winter season and on particularly cold days.