Will a radiation treatment for cancer help patients with irregular heartbeats?

Jeff Backus is fitted with a vest of electrodes to map how his heartbeat goes awry. Doctors are zapping the heart with radiation normally reserved for cancer, a bid to better treat people with life-threatening irregular heartbeats who’ve exhausted other options. But the FDA requires stronger evidence for more routine use — and the more hospitals offer “off-label” radiation to these heart patients, the harder it will be to get that proof. Cuculich thought it would work by simply copying catheter ablation’s scarring but was stunned when scans showed “we weren’t actually causing a new scar — and that’s a big deal.” Rentschler, a developmental biologist who also treats heart patients, took a closer look. Now Rentschler’s research team is testing human heart cells in lab dishes, measuring exactly how they conduct electrical impulses — in hopes that even lower radiation doses might work.