Visit msnbc.com for breaking news, world news, and news about the economy

The death of a 14-year-old Maryland girl last December from a heart attack doctors said was caused by caffeine toxicity is an alarming example of what hospitals are seeing too much of: kids in the emergency room after drinking too many energy drinks.

Anais Fournier, who had a heart condition, drank two 24-ounce energy drinks at the mall last December, the Today show reports:

The next day, the Maryland teenager went into cardiac arrest — and just six days later, she was dead. … The day before she went into cardiac arrest, Anais’s family says she drank two 24-ounce Monster energy drinks, unwittingly guzzling 480 milligrams of caffeine — that’s nearly five times the limit recommended by the American Academy of Pediatrics. To put it another way: By drinking just two large energy drinks, Anais drank as much caffeine as you’d find in about 14 cans of Coke. Monster tells NBC News, ”we vehemently deny that drinking two cans of Monster Energy by itself can cause a death from caffeine toxicity.” The company also points out that their beverages contain less caffeine than some of the drinks sold at Starbucks and other coffee shops.

U.S. health professionals are seeing a more than a 1,000 percent increase in hospital emergency room visits involving energy drinks since 2005, according to a Center for Behavioral Health Statistics and Quality study. In 2005, they logged 1,128 such visits. In 2008 they saw 16,053 and in 2009, 13,114 visits.