Medical Tests Hit Heart Patients With High Doses of Radiation

Nov. 17 -- MONDAY, Nov. 16 (HealthDay News) -- Heart attack patients arriving at the hospital typically receive the radiation equivalent of 725 chest X-rays from medical tests during that single hospital stay, new research shows.

The average exposure was 14.5 millisieverts (mSv), about one-third the annual maximum of 50 mSv allowed radiation workers and more than five times the amount of background radiation Americans get from just going about their business in any given year.

Although the amount may sound alarming, it's not at all clear at this point whether these dosages actually increase health risk, particularly the likelihood of developing cancer, said the Duke University researchers, who plan to present their findings Monday at the American Heart Association's annual meeting, in Orlando, Fla.

"We have to weigh the potential risk of radiation against the risk of not doing anything, and the risk would be very substantial, especially in these patients who were gravely ill," said Dr. Thomas Gerber, a spokesman for the heart association and a professor of medicine and radiation at the Mayo Clinic, in Jacksonville, Fla. "It's important to realize that nobody has ever been able to show scientifically that radiation at the levels used in medical imaging increase the risk of cancer. These are all theoretical concerns that are mathematically extrapolated from what happened in survivors of Hiroshima and Nagasaki who got so much more radiation."

"The actual biological effects of radiation are an ongoing question," added study author Dr. Prashant Kaul, a fellow in cardiovascular medicine at Duke. "The risks of causing cancer at the radiation dose levels we're talking about is actually uncertain."

The findings arrive in the context of several other recent studies that have shown that patients of all kinds are being exposed to large amounts of radiation from medical imaging procedures.

According to background information in this study, radiation exposure from medical imaging procedures exploded more than 700 percent between 1980 and 2006. One-third of these were cardiovascular procedures.