New protocol reduces children's radiation exposure during cardiac procedures

Invasive cardiac electrophysiology is used to diagnose and treat abnormal heart rhythms, or arrhythmias, which can range from the benign to the life-threatening.

In the study, researchers looked at boys and girls at an average age of 14.5 years who underwent electrophysiology procedures to diagnose and treat arrhythmias. In the procedures, doctors use fluoroscopy, which is a continuous X-ray, to visually guide catheters in the heart which are inserted through blood vessels in the groin or neck that lead to the heart.

The downside of this imaging is that it exposes patients to a continuous flow of radiation, said Akash R. Patel, M.D., lead author of the study and an electrophysiology fellow in the Division of Cardiology at The Children's Hospital of Philadelphia in Pa. "Radiation exposure in pediatric electrophysiology procedures is not insignificant. We compared the radiation exposure of 70 children who had undergone the procedures before we began the protocol to that of 61 children who had the procedures after we instituted the protocol."

The new protocol uses a low dose fluoroscopy setting and continuous real-time monitoring of radiation exposure. When the radiation dose registers at certain levels, the physician is notified so that the he or she can adjust the fluoroscopy cameras to minimize exposure.

The researchers found significantly reduced radiation exposure among children whose procedures were performed using the new protocol, including:

• 22 percent reduction in the time that the X-ray machine was on
• 52 percent reduction in the dose of X-ray entering the skin, which helps to prevent skin injury
• 51 percent reduction in median effective dose, which correlates with the lifetime increased risk of cancer from radiation exposure.

"While we did not measure what these lower doses mean in the long run, we presume, for example, that reducing the effective dose will decrease the child's lifetime increased cancer risk from radiation exposure," Patel said.

"The public should be aware of radiation exposure from electrophysiology procedures, and physicians and hospitals should be vigilant in implementing protocols aimed at reducing radiation exposure from these procedures. This is especially important in children to minimize their risk of radiation-induced cancer because they should live for many decades after their procedures."

Co-authors are: Jamie Ganley, B.S.; Xiaowei Zhu, M.S., Jonathan J. Rome, M.D.; Maully Shah, M.B.B.S.; and Andrew C. Glatz, M.D. Author disclosures are on the abstract.

The Children's Hospital of Philadelphia funded the study.