A new pacemaker from Medtronic is all about shrinking: the device reduces the cost and risk of treating heart disease while measuring barely larger than a nickel. Doctors can implant it in the heart using a catheter, rather than invasive surgery, meaning patients will recover far more quickly and experience fewer post-operation complications. A ten-year battery life means less long-term maintenance, though it also means that children won’t be able to use the pacemaker. Clinical trials will test the world’s smallest pacemaker on up to 780 patients around the world.