Putting radiation to the test to heal irregular heartbeat

ST. LOUIS (AP) — 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. 

While it's highly experimental, surprising early research suggests it may reprogram misfiring heart cells to control heartbeats more like younger, healthier cells do. 

“It may actually rejuvenate sick tissue, and that’s pretty exciting,” said Dr. Stacey Rentschler of Washington University in St. Louis. 

An irregular heartbeat called ventricular tachycardia is a major cause of sudden cardiac arrest, blamed for about 300,000 U.S. deaths a year. Treating it with radiation is a radical approach — cancer doctors are trained to avoid radiating the heart at all costs for fear of collateral damage.