Going wireless: New pacemaker goes right in the heart
Paul Schneekloth had always been active. The East Dennis resident was a technician for AT&T during his career years, had three children, played in a softball league, and, in his youth, semi-pro hockey.
And then, at the age of 71, he was tired all the time.
“I’d get up in the morning and get dressed and I’d just be exhausted from getting dressed,” he said. “I was just really fatigued all the time.”
The cause: Schneekloth’s heart rate was too slow and not pumping enough oxygen to his body. He needed a pacemaker to speed up his heartbeat.
His timing was lucky: Several weeks ago, he became the first Cape Cod recipient of a new kind of pacemaker that’s smaller than a AAA battery.
The Micra Transcatheter Pacing System is a long name for a device that is a fraction the size of a standard pacemaker and looks like a large vitamin capsule with tines on the end. And unlike other pacemakers, it is inserted directly into the heart and doesn’t have wires or a separate battery. It is suitable for some patients with a slow heart rhythm known as bradycardia, according to Peter Friedman MD, PhD, FACC, FHRS, a Cape Cod Healthcare cardiac electrophysiologist who implanted Schneekloth’s Micra TPS at Cape Cod Hospital in April.
“For someone who only needs pacing in the lower chamber of the heart, this device is now a good alternative to the standard pacemaker,” Dr. Friedman said.
No Separate Battery
When the heart is pumping too slowly, it can cause dizziness, fatigue, shortness of breath or fainting spells. Pacemakers help by sending electrical impulses to the heart to restore the natural heart rate. From two to four patients a week get pacemakers at Cape Cod Hospital, Dr. Friedman said. He estimates 25 percent of them might qualify for the Micra TPS.
The standard procedure for a pacemaker requires a physician to make an incision below the shoulder and, using X-ray, guide a wire about the width of a cellphone cord down a vein and into the right ventricle of the heart, Dr. Friedman said. The vein into which the wire is inserted is usually easily accessible, but occasionally a needle puncture is required to gain access to the vein. On rare occasions this can cause the lung to collapse, a condition known as pneumothorax.
Once the wire is in good position, the doctor then makes a pocket in the skin and inserts a flat battery about 2 inches in diameter, plugs in the wire, and stitches up the incision. The patient spends a night in the hospital and then, to prevent the wire from dislodging, is prohibited from lifting the left arm above the head or carrying more than five pounds in that hand for up to six weeks.
A postoperative chest X-ray is required before hospital discharge to be certain the wire is in good position and that the lung has not collapsed.
“It’s a reliable device and it’s served us well for a long time,” Dr. Friedman said.
But there are issues with a standard pacemaker. Cosmetically, pacemaker surgery creates a scar and the device bulges in the upper chest. And, about one in eight patients have complications, according to the New England Journal of Medicine.
Depending on how much the heart relies on the pacemaker, the battery must be replaced every five to seven years by reopening the skin pocket, Dr. Friedman said. Because of scar tissue and less blood flow in the area, the risk of infection during replacement is higher than during the original procedure. Also, he said, wires can break down over time.
The Micra TPS eliminates the battery, the wires, and the need for the skin pocket.
To implant the device, the patient is sedated and then the physician makes a tiny incision in the femoral vein in the upper part of the thigh.
Holding a Micra TPS in his fingers like a miniature rocket, Dr. Friedman demonstrated how, attached to the tip of a long catheter, it follows the vein up into the patient’s right ventricle. The physician pushes the device against the wall of the heart, allowing the tines to lodge into the tissue.
After testing to make sure the Mitra TPS is secure and transmitting correctly, the doctor withdraws the delivery device. Pressure, or perhaps a stitch or two, stops the bleeding from the incision in the leg. The patient usually goes home the same day. There are no restrictions on movement or physical activity, and no post-operative chest X-ray is required.
“It doesn’t have wires to malfunction; there’s no risk of collapsing a lung, there’s no bulge and cosmetically, it’s nicer,” Dr. Friedman said.
Happy To Feel Better
Schneekloth said he isn’t even aware of the Mitra TPS in his body, except in a good way.
“I’m 100 percent better,” he said. “I can cut the grass. I can’t push the lawn mower and cut the grass, but I can sit down on it. I can walk a lot further without getting tired.”
The battery is likely to last 12 years and, if it loses power or fails, another one can be inserted next to it, Dr. Friedman said. The main risks of the Micra TPS, he said, are that it would dislodge and travel out of the right ventricle, or that something goes wrong during insertion and the wall of the heart is punctured.
Researchers at the University of Oklahoma and other sites reported in a November 2015 issue of the New England Journal of Medicine on Micra TPS implants in 725 patients. The device was successfully implanted in 99.2 percent of the patients and 96 percent of them had no major complications after six months.
Several weeks out, Schneekloth was happy with the results and looking forward to his six grandchildren coming to his East Dennis house this summer.
“I’m glad I’m feeling better,” he said.