Radiation therapy may offer a comparable and potentially safer alternative to repeat catheter ablation for patients with severe abnormal heart rhythms that can no longer be controlled with medication.

“For patients who do not respond to traditional therapies and are at high risk of complications, noninvasive radiation may be a safer alternative to repeating an invasive catheter ablation procedure,” said lead researcher Dr. Shannon Jiang, a radiation oncology resident at Washington University School of Medicine in St. Louis.

Radiation levels downwind of U.S. hydraulic fracturing drilling sites tend to be significantly higher than background levels, posing a potential health risk to nearby residents, according to a study by Harvard researchers released on Tuesday.