The new pacemaker, sitting in the palm of the hand, looks like a large titanium vitamin pill.
That tiny device, implanted recently for the first time in West Michigan, represents a “complete revolution” in pacemaker technology, said Andre Gauri, MD, section chief of cardiac electrophysiology at the Spectrum Health Fred and Lena Meijer Heart Center.
About one-tenth the size of a traditional pacemaker, it is small enough to be delivered through a catheter.
“It’s mind-boggling,” said Herb Carpenter, 86, as he waited to become the first local patient to receive the new device on Sept. 28. “It’s wonderful for the patient.”
There are certain devices that are evolutionary. This is truly revolutionary.
The value of the Micra Transcatheter Pacing System created by Medtronic lies not just in its small size, but in the way the system works, Dr. Gauri said.
“It’s a pacemaker and a lead all in one device,” he said.
Traditional pacemakers consist of a wire, or lead, that attaches to the wall of the heart and threads through a vein to a battery pack, worn under the skin in the chest. When the heart rate falls too low, the battery delivers a pulse of electricity through the wire to the heart to stimulate a consistent heartbeat.
“The Achilles heel, or the weak part, of the (traditional) pacemaker system is that leads can break or become infected and may need to be replaced or removed from the heart, which is a challenge,” Dr. Gauri said.
The new Micra pacer does not require a cardiac wire. The cardiologist places the miniature device in the chamber of the heart. Little metal tines attach to the web-like muscle fibers. The electrode on the device delivers electrical impulses directly to the heart.
The new technology could have a big impact. More than 500,000 Americans use pacemakers to treat abnormal heart rhythms.
“There are certain devices that are evolutionary,” Dr. Gauri said. “This is truly revolutionary. It’s a whole other paradigm within the pacer world.”
A fly-fishing comparison
On Sept. 28, Carpenter became the fifth patient in the state and the first in West Michigan to receive the Micra pacemaker since it received U.S. Food and Drug Administration approval April 16.
A retired dentist from Grand Rapids, Michigan, Carpenter became a candidate for a pacemaker when his heart rate dropped to about 47 beats per minute. He began to notice problems last Christmas. He became short of breath when he took long walks or worked out on a treadmill or exercise bike.
His cardiologist determined he had aortic stenosis and needed an aortic valve replacement, as well as a pacemaker. He got the pacemaker first.
“I want to stay healthy,” Carpenter said as he waited to go into the catheter lab. “I like my independence. I want to socialize and to go up north with my son.”
As Dr. Gauri showed him the tiny pacemaker, he held the device in his hand and looked at it closely. It measured about an inch long and about 1/4-inch in diameter.
“It looks like a fly,” he said, meaning the kind of fly his son uses for fishing. The tines on the end look like fish hooks, he added.
Carpenter said he welcomed the chance to be a medical pioneer.
“It’s an improvement. Why not get the newest and latest and the best?” he said. “I’m thrilled in a way. I can see right off the bat it’s better than having wires in your heart because your heart’s moving all the time.”
In the lab, Dr. Gauri inserted a catheter into Carpenter’s femoral vein in the groin and up to the blood vessel to the heart.
He threaded the Micra pacer through the catheter and secured it in the right ventricle. Like other pacemakers, it is programmed to sense when the heart rate drops too low and to deliver an electrical impulse.
‘The wave of the future’
The day after he got the pacemaker, Carpenter had his aortic valve replaced with an artificial valve. The procedure, done through a catheter, was performed at Spectrum Health’s Transcatheter Aortic Valve Replacement (TAVR) Clinic.
A week later, during a physical therapy appointment at home, he noticed improvements.
“I think I was able to do more walking than I would have previously,” he said.
An avid golfer, he hopes to get strong enough to get back out on the course.
The Micra pacemaker’s battery will last about 10 years, said Justin Sweet, a technical field engineer for Medtronic. When the battery runs low, a cardiologist can implant a second pacemaker next to the first. The device is designed to be left in the body.
The new pacemaker carries a psychological benefit, he added. It does not include a scar and bump under the chest skin, as traditional pacemakers do. Such factors provide “a constant reminder of the fact there’s something in there supporting them,” he said.
Patients with the pacemaker also can receive full-body MRIs. It is the only pacing system approved for both 1.5 Tesla and the more powerful 3 Tesla MRI scans, Medtronic says.
“I think this is really the wave of the future for pacemakers and defibrillators,” Dr. Gauri said.