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Harvard Heart Letter | July 2008
Heart beat
Heart-stopping thrills
When
a roller coaster advertises heart-stopping action, it may not be an
empty boast. On average, four people die each year from roller coaster
rides. About half of the deaths are caused by accidents, inebriation or
foolish behavior, and mechanical failure. The other half are due to
medical conditions, mostly heart attacks, lethal arrhythmias, bleeding
into the brain, or ruptured blood vessels.
Two studies of
roller coaster riders showed that the heart starts pounding almost as
soon as the cars begin their first climb. Peak heart rates among the
generally young and healthy volunteers averaged 155 beats per minute,
with some riders hitting 90% of their maximum heart rates in under a
minute. Blood pressure also spikes. In one of the studies, published in
2007 in The Journal of the American Medical Association, about
half the volunteers had irregular but harmless heartbeats for several
minutes after the ride had ended. Whether the irregularities would be
harmless in people with heart disease is an open question.
It’s
conceivable, though unknown, whether newer rides might have even
greater effects on the cardiovascular system. Some of the newest rides
top 100 miles an hour and reach G-forces similar to those experienced
at liftoff by space shuttle astronauts.
The vast majority
of people who loop-the-loop walk away from the ride with a thrill and
nothing more. But there’s a reason why roller coasters and other rides
prominently post a warning for folks with heart disease.
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