Pacemaker surgery typically requires a doctor to make an incision above a
patient’s heart, dig a cavity into which he can implant the
heartbeat-regulating device, and then connect the pulse generator to
wires delivered through a vein near the collarbone. Such surgery could
soon be completely unnecessary. Instead, doctors could employ
miniaturized wireless pacemakers that can be delivered into the heart
through a major vein in the thigh...
http://www.technologyreview.com/news/522306/worlds-smallest-pacemaker-can-be-implanted-without-surgery/
