Medtronic setting the pace with Micra

Medtronic is racing to sell Micra, a pacemaker so small that it rests inside the heart itself.

Unlike traditional pacemakers implanted under the skin, the tiny experimental model is slipped on a catheter through the femoral artery and docked, in its entirety, inside the right ventricle. It operates there without electrical wires that can break or get infected.

Medtronic started work on shrinking the pacemaker in 2009, with the goal of making it a 10th its existing size. More efficient electronics meant they could use a smaller battery, that can last at least 12 years, and put the electrode directly on the mini-pacemaker to eliminate wires.

John Day, director of heart rhythm services at Intermountain Medical Center in Salt Lake City and president of the Heart Rhythm Society, said: “It’s definitely going to be disruptive technology.”

For now, the mini-pacemakers are only for patients who need electronic pacing of a single chamber of the heart which is about 30 percent of the 1 million pacemakers implanted each year.

David Steinhaus, vice president of Medtronic’s heart rhythm unit, said: “We believe this may be the future of pacing. In the next 10 years there will be a dramatic increase in the technology that allows this all to happen.”

Day said: “A traditional pacemaker sits under the skin below the shoulder, with one, two or three wires running through a vein that attach to the heart. The wires can cause blood clots in the veins, scar tissue formation or infections. The mini-pacemaker lowers those risks, there is nothing visible in the chest, there are no wires to break.”

Medtronic completed enrolling patients in its U.S Micra trial early, without any major complications from the implantation.

Robert Schwartz, medical director at the Minnesota Cardiovascular Research Institute and a cardiologist at Minneapolis Heart Institute, said: “These are the first generation devices. There are a lot of exciting things coming.”