Effect of Hurricane Katrina on chronobiology at onset of acute myocardial infarction during the subsequent three years.

The onset of acute myocardial infarction (AMI) has been shown to occur in a nonrandom pattern, with peaks in midmorning and on weekdays (especially Monday). The incidence of AMI has been shown to increase locally after natural disasters, but the effect of catastrophic events on AMI biorhythms is largely unknown. To assess the differences in the chronobiology of AMI in residents of New Orleans before and after Hurricane Katrina, the onset of AMI in patients at Tulane University Health Sciences Center in the 6 years before and the 3 years after Hurricane Katrina was retrospectively examined. Compared to the pre-Katrina group, the post-Katrina cohort demonstrated significant decreases in the onset of AMI during mornings (p = 0.002), Mondays (p <0.0001), and weekdays (p <0.0001) and significant increases in onset during weekends (p <0.0001) and nights (p <0.0001). These changes persisted during all 3 years after the storm. In conclusion, the normal pattern of AMI onset was altered after Hurricane Katrina, and expected morning, weekday, and Monday peaks were eliminated.