"For people with known heart disease, we strongly recommend passing on the roller coaster," says researcher Jurgen Kuschyk, MD, a heart specialist at University Hospital in Mannheim, Germany.
On Tuesday, the June 13 death of a 4-year-old boy with a heart defect -- who died after riding a thrill ride at Walt Disney World in Orlando, Fla. -- was attributed to an abnormal heart rhythm.
A Ride's Impact on the Heart
The study, presented at the annual meeting of the American Heart Association, included 55 adults who went on Expedition GeForce, a 120-second ride that starts with a slow, 203-foot ascent followed by a free fall at a maximum speed of 75 miles per hour. Thirty of the participants had never ridden a roller coaster before.
With changes in gravity of 6 g's in four seconds, the ride's "gravity forces are like the astronauts," Kuschyk says.
All the participants had a thorough physical examination to rule out heart disease before taking part in the study. But during the ride, one person's heart rate soared above 200 beats per minute -- fast enough to cause dangerous heart rhythms and potentially deadly for someone with heart disease.
About half the participants experienced temporary irregular heartbeats that were not life-threatening. On average, heart rates rose from 91 beats per minute before the ride to 153 a minute later.
The Role of Stress
Stress and fear, not increased g-force, were probably to blame for the skyrocketing heart rates, Kuschyk tells WebMD.
Noting that there is trend toward building roller coasters that are even faster and steeper than the last, he says it's important to realize the rides' potential dangers.
The magnetic brakes on coasters can interfere with the function of pacemakers, he says. Another concern is a potential interaction between stress of the ride and alcohol, which was recently blamed for the death of a man in Germany during Oktoberfest.
Warning Signs Ignored
Kuschyk says most amusement parks post signs warning people with heart conditions not to ride the coaster but that the signs are typically ignored.
Lynn Smaha, MD, PhD, a former president of the American Heart Association and a cardiologist at the Guthrie Clinic in Sayre, Pa., says more research into the impact of amusement park rides on the heart is needed.
For now, however, there is no reason healthy people shouldn't enjoy the thrills, he says.
Kuschyk agrees that people with strong hearts can relax. "For healthy people, I don't see a problem," he says.