Disaster events and the risk of sudden cardiac death: a Washington State investigation.

BACKGROUND Psychological distress following disaster events may increase the risk of sudden cardiac death. In 2001, the Nisqually earthquake and the 11 September terrorist attacks profoundly affected Washington state residents. HYPOTHESIS This research investigated the theory that the incidence of sudden cardiac death would increase following these disaster events. METHODS Death certificates were abstracted using a uniform case definition to determine the number of sudden cardiac deaths for the 48-hour and one-week periods following the two disaster events. Sudden cardiac deaths from the corresponding 48-hour and one-week periods in the three weeks before the events, and the analogous periods in 1999 and 2000 were designated as control times. Using t-tests, the number of sudden cardiac deaths for the periods following the disaster events was compared to those of the control periods. RESULTS In total, 32 sudden cardiac deaths occurred in the four counties affected by the Nisqually earthquake during the 48 hours after the event, compared to an average of 22 +/- 3.5 (standard deviation) in the same counties during the control periods (p = 0.02). No difference was observed for the one-week period (94 compared to 79.2 +/- 12.4, p = 0.28). No difference was observed in the number of sudden cardiac deaths in the 48-hours or one-week following the terrorist attacks compared to control periods. CONCLUSIONS A local disaster caused by a naturally occurring hazard, but not a geographically remote human disaster, was associated with an increased risk of sudden cardiac death. A better understanding of the underlying mechanisms may have implications for prevention of sudden cardiac death.