Heart attack pattern shifted after Katrina

 Heart attacks are usually most common on weekdays and mornings, especially Mondays, but new data analysis shows that pattern reversed in New Orleans after Hurricane Katrina.

"The fact that it's such a polar opposite shift is really surprising," lead author Dr. Matthew Peters of Tulane University told Reuters Health.

After the storm the overall number of attacks tripled, likely due to an increased number of smokers. They were more likely on weekday evenings and weekends, according to data published in The American Journal of Cardiology.

Before the hurricane, 23 percent of heart attacks happened on Mondays, in line with national averages. After, 10 percent happened on Mondays, less than any other day of the week.

Previous research has attributed the usual excess of Monday and morning heart attacks to work stress, which also peaks on Mondays and in the morning. Researchers were puzzled to find the pattern reversed after the hurricane.