One Halloween night in 1957, a power outage in the Minneapolis area threatened lives when hospital pacemakers shut down. Back then, pacemakers were the size of large electronics and were plugged into electrical outlets.

Unfortunate at the time, but it encouraged the invention of the first battery-powered pacemaker. Medtronic’s flagship battery-powered device revolutionized pacing therapy and supercharged growth—the company’s Cardiovascular portfolio reached over $12 billion last year.

Ten years ago, the company brought a new pacemaker to market—Micra. Micra is less than a tenth the size of a typical pacemaker, comparable in size to a large vitamin. It’s also minimally invasive and implanted directly into the heart, removing possible sources of complications and helping people feel better without physical reminders that they even have a pacemaker.

Dr. Rob Kowal, a former electrophysiologist at Baylor Heart and Vascular Hospital, is the vice president and general manager of Medtronic’s Cardiac Pacing Therapies business. Dr. Kowal recalls meeting the engineers behind Micra at a medical conference over a decade ago—they placed a small piece of metal that resembled a fishing weight in his hand and asked: “What do you think about a new kind of pacemaker this size, without wires that go into the heart?”

Inspired, Dr. Kowal left his private practice and joined the team behind this idea. Ten years later, Micra is still the world’s smallest pacemaker. The company said over 300,000 patients have received a Micra pacemaker and it boasts 40% more battery life, meaning current generation Micra pacemakers may not need device changes for most patients.

To gain more insights on Micra, MPO spoke to Dr. Kowal about its invention, innovation, and future.

Sam Brusco: How did the idea for Micra come about?

Dr. Rob Kowal: At Medtronic, our Mission to alleviate pain, restore health, and extend life drives everything that we do. That purpose, combined with a relentless focus on improving the patient experience, led to the development of the Micra leadless pacemaker.

For more than 70 years, implantable pacemakers have helped millions of patients feel better and get back to doing the things they love. Over time, iterative improvements and new features like MR-conditionality, rate-responsiveness, and advanced programmability have made a big difference for patients, but the core design remained the same: a battery-powered device placed under the skin of the upper chest, connected to the heart via wires, or leads. While the complication rate for traditional pacemakers and leads remains low, both the subcutaneous location of the pacer and the leads can occasionally pose risks for some patients.

As technology miniaturization advanced, we asked: how can we make pacing therapy even better for patients? That question led us to challenge our own legacy and pursue a leadless design by eliminating both the subcutaneous device and the leads, and instead implanting a pacemaker directly into the heart. Ten years ago, we launched Micra, the world’s smallest pacemaker, disrupting the pacing therapy we pioneered. It’s a powerful example of how we can transform mature markets and therapies when we reimagine what the patient experience can, and should, look like.

Brusco: What technological innovations were needed to make Micra possible?

Dr. Kowal: We wouldn’t be able to talk about technological innovations and Micra without discussing the importance of miniaturization. The engineers who worked on Micra developed ultra-compact electronics and an incredibly small, yet still long-lasting, battery to shrink all the necessary parts of a pacemaker down to the size of a large vitamin, more than ten-fold smaller than our traditional devices.

Without leads, engineers had to find a new way to help anchor the small pacemaker where it is needed in the heart. They developed tiny, flexible nitinol tines, which resemble tiny hooks, that securely attach Micra to heart tissue.

A minimally invasive delivery system was another key innovation. Physicians implant Micra using a specially designed catheter inserted through the femoral or jugular vein, enabling placement directly into the heart without surgery.

To sense a patient’s activity as well as their heart’s movements to adjust pacing, Micra uses an internal accelerometer. Wireless communication technology allows doctors to program and monitor the device remotely, further enhancing patient care.

Overall, the combination of miniaturized electronics, a leadless fixation system, minimally invasive delivery, advanced materials, and integrated sensing and communication made Micra’s revolutionary design possible.

Brusco: How does Micra differ from traditional pacemakers?

Dr. Kowal: Traditional pacemakers are placed in a patient’s chest, under the skin near the collar bone, with leads (thin wires) threaded through veins and into the heart. The incision to implant the pacemaker may leave a scar on the chest, and the patient may see and/or feel a bump under their skin once the pacemaker is in place.

The Micra leadless pacemaker, however, is implanted entirely within the heart during a minimally invasive procedure that requires no chest incision. It is inserted with a catheter through a vein in the groin or neck, and it does not create a scar or bump under the skin once it is in place. For most patients, the smaller leadless Micra design may translate into fewer medical complications and fewer post-implant activity restrictions.

Brusco: What’s ahead for Micra and cardiac pacing technologies in the next ten years?

Dr. Kowal: Right now, not every patient has the option to receive a single, leadless device to provide the pacing therapy they need. Looking ahead, our goal is to make leadless pacing an option for every patient who can benefit from it.

Beyond that, just as Micra reimagined what a pacemaker looks like, we’re now also reimagining what a pacemaker can do. We’ve seen exciting progress in conduction system pacing (CSP), a pacing approach that stimulates the heart’s natural electrical pathways to induce a more physiologic response. Advancements in CSP are opening doors to exploring how pacemakers could help treat new patient populations.

One of the ways we’re doing just that is by initiating large, global trials like ELEVATE-HFpEF, to look at how personalized pacing that leverages CSP might help patients with heart failure with preserved ejection fraction. We also have a strategic collaboration with Orchestra BioMed on the BACKBEAT Global Pivotal Trial that is investigating atrioventricular interval modulation (AVIM) therapy as a potential treatment for uncontrolled hypertension in pacemaker-indicated patients.

Brusco: Can you describe the experience of transitioning from clinical work to working with Medtronic, what you expected, and what you didn’t expect about making Micra a reality?

Dr. Kowal: Leaving private practice to pursue medical technology was a significant career shift, and it was absolutely thrilling and enriching. I was in private practice when Medtronic first launched Micra, and I had the opportunity to participate in the Global Pivotal Trial as a physician investigator. I saw where innovations in pacing therapy were headed, and I knew I wanted to be part of shaping that future. The chance to help drive innovation—not just adopt it—was, and still is, incredibly motivating.

Coming to Medtronic, I expected to work with brilliant engineers and clinicians, and that’s absolutely been true. What I didn’t expect was the scale of impact a company like Medtronic can have. In private practice, I valued the one-on-one relationships I was able to build with patients. While I miss that direct connection, I’ve gained the ability to help people on a global scale at Medtronic. The technologies we develop, game-changing advancements like Micra, can reach thousands, even millions, of patients around the world. That’s humbling and energizing.

As we keep the patient experience at the center of everything we do, we’ll continue to push boundaries by finding new ways for more people to benefit from pacing therapy. I cannot think of a better way to honor and serve the Medtronic Mission to alleviate pain, restore health, and extend life.