Heart Problems Prompt Fainting Behind the Wheel
May 17, 2000 (Washington) -- People involved in car accidents that occur
under mysterious circumstances may have passed out at the wheel due to a
common, but often undiagnosed, heart condition, according to researchers at
The researchers are specialists in testing used to diagnose irregular
heartbeats and other disorders in which the heart may beat too fast or two
slow. They want to warn people who may have "fainting spells" not to
ignore them, because they are likely to happen again and can be treated, Mark
H. Schoenfeld, MD, tells WebMD. Schoenfeld is the director of the heart testing
lab at Hospital of San Raphael and an associate professor at Yale University
School of Medicine in New Haven, Conn.
Schoenfeld and his colleagues studied the results of tests performed over
the past 14 years on patients who were referred to them after an accident. In
all cases, their primary care doctor and a cardiologist had been unable to
determine what caused their crash.
"Most of these patients come to us with their doctors throwing up their
hands in frustration, and the patients are even more frustrated than the
physicians because they are fearful of going back to driving," he says.
"All of the patients referred to us say, 'I did not fall asleep.' A lot of
times, they will have a passenger in the car, and they will say, 'This patient
just slumped over, or they turned white, or they just didn't look right, or
they were just dazed, or their eyes rolled back.'" Schoenfeld adds that for
many patients, this happened more than once.
"About 80% of the patients who underwent the evaluations that we
performed were found to have an otherwise unsuspected [heart] condition that
could well explain why they had their events," he says. "And
furthermore, treatment of that condition has allowed them to go back to
Testing on the patients' hearts revealed that some of them had rapid
heartbeats that were most often caused by an extra electrical circuit in their
hearts, a condition that they could have been born with. This causes their
heart to speed up, leading to a drop in blood pressure, less blood supply to
their brain, and ultimately a fainting spell, Schoenfeld explains.
In some cases, surgery is required, and medication is used for others. In
all but one of the patients studied in the lab, patients had no more incidents
of fainting while driving, he says.
These episodes seem to be more common among elderly people, but can occur at
all ages, Schoenfeld says. There also is no clear pattern of the spells. "I
have patients that have had four separate spells in 17 years. I have patients
who have one spell a year. I have patients who can go 20 or 30 years without a
spell before another spell," he says.