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Heart Disease Health Center

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Heart Problems Prompt Fainting Behind the Wheel

WebMD Health News

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 Yale University.

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 driving, safely."

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.

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