Radiation therapy often is used to treat cancer patients. Now, doctors at Washington University School of Medicine in St. Louis have shown that radiation therapy — aimed directly at the heart — can be used to treat patients with a life-threatening heart rhythm. They treated five patients with irregular heart rhythms, called ventricular tachycardia, who had not responded to standard treatments. The therapy resulted in a dramatic reduction in the number of ventricular tachycardia episodes.