Studying medical records from the 2006 World Cup soccer tournament in Germany, researchers reported Wednesday that they found the rate of heart attacks for Munich-area residents more than doubled on days that the German national team played.
During the two most nerve-racking games for Germany -- a match against Argentina that was won on penalty kicks and one against Italy that knocked Germany out of the final -- the heart problems spiked to four to five times the normal rate, said Dr. Gerhard Steinbeck, professor of internal medicine and cardiology at the University of Munich and the senior author of the study.
The study, published in the New England Journal of Medicine, is a clear warning for Super Bowl fans Sunday, said Dr. Riyaz Sumar, an intervention cardiologist affiliated with Maryvale Hospital Medical Center in Phoenix, a few miles from the site of the big game.
Sumar will be one of several cardiologists and extra nurses on call all weekend. "Once it gets too exciting, I'll be standing in the ER, waiting for them to come in," he said.
The study confirms what sports fans have long known: It's heart-pounding to watch your team in a tough spot.
Science, however, has not been so certain. Previous studies looking at the relationship between sporting events and cardiac emergencies have found contradictory results.
In the latest study, researchers examined a series of games rather than just one, and controlled for a wider variety of confounding factors, including temperature and air pollution.
Steinbeck and his colleagues looked only at the records of Munich-area residents, excluding heart attacks among tourists visiting during the soccer tournament. They focused on cardiac emergencies such as heart attacks, severe chest pain and serious heart rhythm abnormalities.
The researchers looked at 4,729 records drawn from the month of the World Cup (June 9 to July 9, 2006), along with control periods before and after the tournament and three summer months in 2003 and 2005.
Compared with ordinary summer days, Munich-area residents had 2.66 times more serious heart problems on days that Germany was playing, the researchers found. There was no significant increase on days that Germany did not play, Steinbeck said.
The stress appeared to be greatest on men and people with known coronary artery disease, who saw the incidence of cardiac emergencies rise by factors of 3.26 and 4.03, respectively.
Sleep deprivation, junk food consumption and failure to remember to take medications may have contributed to the heart attacks, but Steinbeck's group also found a close relationship between the onset of pain and the start of the games.
"This makes us sure that indeed the stress and tension caused by the games probably also caused these emergencies," Steinbeck said.
Steinbeck, a longtime soccer fan, said he could vouch for the "intense strain" Germans felt during those games because he felt his own blood pressure rise and heart race.
American football fans would do well on Super Bowl Sunday to heed the lessons from the German study, but they don't have to shut out the game completely, said Dr. Malissa Wood, a cardiologist at Massachusetts General Hospital who was not involved with the study.
Fans with heart problems should remember to take their medications, and everyone should try to stay away from fatty foods, she said.
"If you feel yourself getting frustrated, switch off the TV and talk to a loved one," Wood said. "Realize it's just a game, and it's really not worth it."
Still, Wood, who is a fan of the New England Patriots, said she doubted her hospital would see too many patients on Super Bowl Sunday.
"I don't think Massachusetts fans are going to have any worries because the Pats are going to play a good game," she said.