More than 200,000 pacemakers are implanted in the U.S. each year to control a heart rate that is either too fast or too slow. Conventional pacemakers are inserted into a pocket created by a surgeon under the collarbone. Long electrical wires, also called leads, are placed inside the heart. The sensors at the leads’ tip detect and regulate the heart’s electrical activity, which controls heart rate and rhythm. Stitches are required to close the incision.
“The weak link in current pacemakers is that they need leads,” said Jonathan Piccini, MD, a Duke electrophysiologist. “They have to twist and bend through blood vessels and they bend repeatedly with each heartbeat – your heart beats about 100,000 times each day -- which can strain the wires.” The leads can also clog veins or become embedded in the heart tissue after years of use. That can hamper surgery to replace a pacemaker that has become infected or when the leads need to be replaced or upgraded.