Leadless Pacemaker Offers New Option for Bradycardia

The world’s smallest pacemaker is placed directly on the heart to stimulate a normal heart rhythm, and does not require the use of leads.

The miniaturized Micra transcatheter pacing system (TPS) is delivered via a percutaneous catheter to the inside wall of the right ventricle, with small nitinol tines used to hold the device and the electrodes in place. The device can be repeatedly repositioned in the ventricle to make sure heart activity and low electrical thresholds are optimal. Once in position, the device responds to patients' activity levels by automatically adjusting electrical impulses to regulate heartbeats, in the same fashion as traditional single chamber pacemakers. The device consists of a bipolar pacing anode and a steroid-eluting cathode that is separated from the tines to provide optimal contact with the myocardium.

Less than one tenth the size of a conventional pacemaker, The Micra TPS does not require a surgical pocket under the skin or future extraction once the battery is depleted, eliminating potential sources of complications. Despite its miniaturized size, the device has an estimated 12-year battery life, and is also approved for both 1.5 and 3 Tesla full body magnetic resonance imaging (MRI) scans. The Micra TPS is a product of Medtronic (Dublin, Ireland), and has been approved by the U.S. Food and Drug Administration (FDA).

“Dating back to the development of the first external battery operated pacemaker more than 60 years ago, Medtronic has a long history of collaborating with clinicians to better understand the needs of patients, and then innovating new products to meet those needs,” said John Liddicoat, MD, senior vice president of Medtronic. “We are thrilled to be the first to introduce a transcatheter pacemaker to patients in the U.S., and we're looking forward to working with physicians and educating implanters to extend the positive results of our global clinical trial experience to even more patients.”

“For many years we've been hopeful that a transcatheter pacing solution, with a safety and effectiveness profile on par with conventional devices, would become available, and today Micra has achieved this milestone,” said Professor Dwight Reynolds, MD, of the University of Oklahoma Health Sciences Center (Oklahoma City, USA), and principal investigator in the Micra TPS global clinical trial. “In the clinical trial, the Micra was successfully implanted in nearly all patients, and met its safety and effectiveness endpoints by wide margins. This gives us great confidence that this miniaturized device will bring patients the most advanced pacing technology, combined with the less-invasive nature of the new technology.”

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