Health & Medicine

One inch long and as slender as a pencil, this device helps prevent heart attacks

The traditional pacemaker, bottom, dwarfs the new Micra Transcatheter Pacing System and a nickel.
The traditional pacemaker, bottom, dwarfs the new Micra Transcatheter Pacing System and a nickel. Cathie Anderson

The world’s smallest pacemaker made its debut in the Sacramento region this summer when Dr. Mark Bowers implanted one of the slender, inch-long devices directly inside the heart of electrical contractor Eugene Gini at the Alex G. Spanos Heart & Vascular Center at Mercy General Hospital.

Gini was an ideal candidate, Bowers said, because he belongs to a small subset of patients whose slow heart rate can be adjusted by stimulating just one chamber of the heart. Unlike its predecessors, the Micra Transcatheter Pacing System does not employ multiple lead wires to deliver a jolt of energy to the heart. Rather, it stimulates the heart through tines that protrude from it and attach to the lower, right ventricle wall.

However, more patients than not need wire leads in an upper and a lower chamber of the heart, Bowers said, so to some degree, the new Micra is a niche device. Roughly 200,000 people a year receive pacemakers in the United States, but Medtronic spokesman Todd Moore said only about 10 percent of that population would likely qualify for a single-chamber pacemaker like the Micra. Young people have to be excluded from the market, he said, because the device is made to never be removed.

Since Gini’s surgery, Sacramento-area doctors have done only a few other Micra implants. The device was developed by Medtronic, a company that makes other pacemakers which are about the size of a credit card. Surgeons implant the bigger pacemakers in a pocket under the skin near the collarbone on the left side of the chest, then guide the leads through blood vessels and attach them to the heart wall.

“With a traditional device, the leads can fracture. They can pull out,” said Bowers, who specializes in cardiac electrophysiology. “You can get infection of the pocket, which, if it happens early on, is just something you pull out and move it on the other side. But if it’s serious, it can extend all the way down to the heart and cause endocarditis, which is an infection of the heart. It’s not real common, but it could be deadly.”

The Micra’s recovery period is days, not weeks, Bower said. Patients with traditional pacemakers must wait six weeks before they can go back to full activities such as golfing or swimming and before they can do any kind of heavy lifting — even if everything goes well, Bowers said. Otherwise, they could risk pulling out the leads before scar tissue has secured them.

Gini, the majority owner of Stockton-based Collins Electrical Co., had his surgery July 24 and was out golfing by Aug. 2. He said he feels better now than he has since he was fitted with a traditional pacemaker in 2014. The new Micra pacemaker, he said, has corrected several strange sensations he encountered with his old device.

“When I bent over to tee up a (golf) ball, I would have to stand there and wait for about 15 seconds to get the blood rush out of my head, and then I’d hit the ball,” Gini recalled. “Whenever I’d go to meetings, I would doze off in the middle of the meeting. I just didn’t have the stamina. ... The new pacemaker has solved a lot of the problems.”

Gini had been experience blood clots with his previous device, he said, so he went into surgery expecting Bowers to replace his old pacemaker with another one with leads. But the medical team wakened him from his surgery with the news that leads just wouldn’t work in his blood vessels, he said, and they suggested either repositioning a traditional pacemaker on his right side or using the new Micra.

“We’ve been told by our peers that we’re in the top percentile of the industry, as far as our technology,” Gini said. “It seemed appropriate for me to try something like this, and that’s what I did.”

Gini said it’s also fitting that he had his surgery at the Spanos Heart Center because his 90-year-old company was the electrical contractor for the building completed in 2014 and because developer Alex Spanos is a family friend.

Bowers said he’s often asked whether the smaller Micra has as much battery life as the larger, traditional pacemakers. The Micra’s battery has an average life of 12 years, said Medtronic’s Moore, while the company has seen its traditional pacemakers run for an average of 10-12 years. While the larger pacemaker does have a bigger battery, he said, there’s a resistance in the leads that sucks up a lot of energy.

What Bowers likes most about the Micra is that implanting it is a less-invasive procedure. The Micra, he said, is so small that he and other surgeons can make an incision in a vein in the groin and feed the device through the blood vessel and into the heart.

The one complication surgeons have seen is that the tines have occasionally perforated the heart and caused bleeding, Bowers said, consequently they have to ensure the Micra is positioned closer to the septum where tissue is tougher rather than in apex of the heart.

The Micra technology was approved and used in Europe years before the U.S. Federal Drug Administration gave it the OK, Bowers said, so U.S. physicians are benefiting from what European doctors have learned.

Bowers, 40, has been a physician for about 12 years and has practiced cardiology for six years. He said that what many patients also like is that the Micra quickly disappears from view. That isn’t true of traditional pacemakers.

“There’s also a psychological factor when people have these (traditional) devices,” Bowers said. “They’re reminded that there’s something wrong with their heart. They see the scar. They see the bump from the device. I think they’re constantly reminded of their own mortality. There’s a certain stress or anxiety level there.”

With the Micra, you have an incision from putting the catheter in the groin, he said, but there’s no significant pain or healing involved.

About 10 days after Bowers completed Gini’s surgery at the Spanos Heart Center, Dr. Thomas Tadros implanted a Micra into East Sacramento resident Sarah Smith at Sutter Medical Center in midtown Sacramento’s Sutter District. The tiny Micra is not removed at the end of its battery life, Tadros said.

“If you need to have more over your lifetime, they will fit in fine without any issue because they’re so tiny, whereas with the old pacemakers, you had to take out the old one,” Tadros said. “That involved making another incision in the chest, taking out the old one and putting in the new one. Every time you do that, there’s a risk of infection, there’s a risk of damaging the wires and so it’s just wonderful to eliminate those things.”

Cathie Anderson: 916-321-1193, @CathieA_SacBee

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