The device is less than 10 percent the size of a conventional pacemaker. Unlike other pacemakers, it does not have wires -- called leads -- that snake into the heart. Instead, the tiny pacemaker is implanted directly into the heart itself.
Nanostim is for patients who need "single-chamber pacing" -- that is, only a single ventricle needs its rhythm sped up. But Dr.
"We are certainly interested in bringing leadless technology to the full spectrum of pacing for patients," he said in an interview. "This is the initial endeavor. This is the logical and good place to start."
St. Jude's Leadless II trial is designed to evaluate the Nanostim for
St. Jude has had its share of issues with leads. In 2010, it pulled its Riata defibrillator lead from the U.S. market because of problems with inner wires coming through outer insulation. Its QuickSite and QuickFlex pacemaker leads also were pulled for the same reasons.
Besides avoiding design flaws with leads, St. Jude said the new device will reduce complications and improve patient comfort. Cardiologists must create a "pocket" just beneath the skin of the patient's chest to hold a traditional pacemaker generator. Doctors can implant Nanostim without such surgery, inserting it into the heart with a catheter that is steered up through a vein in the leg.
St. Jude said the Nanostim is fully retrievable, meaning that it can be repositioned during the implant procedure and later removed from the heart if necessary.
"I believe this pioneering, compact device, which is placed directly inside the heart, may be a true game-changing technology in cardiovascular medicine and may help revolutionize care for patients with arrhythmias," said Reddy, the study's co-investigator and director of electrophysiology services at
The Nanostim also eliminates the visible lump and scar that come with a conventional pacemaker. St. Jude said that could mean an improved quality of life for patients by allowing them to live more-active, uninhibited lifestyles.
St. Jude is not alone in developing tiny leadless pacemakers. St. Jude acquired Nanostim in October of last year, instantly giving the
Then, in December, Medtronic announced the Micra Transcatheter Pacing System in
St. Jude's Nanostim is the first to proceed to clinical trials in
Cardiac pacemakers treat bradycardia, which is a heart rate that is too slow. More than 4 million people worldwide have an implanted pacemaker or other cardiac rhythm management device, and an additional 700,000 patients receive the devices each year.
'I want to live'
Three days ago,
Nanostim is his first pacemaker.
Dobin, whose heart rate was dropping as low as 28 beats per minute, said doctors told him the device would be less invasive than a conventional pacemaker, yet perform just as well.
"I was close to death. I want to live," said the man who emigrated to
Said his daughter: "It took them a lot longer to prep him before the surgery than it did to do the procedure itself."
The Leadless II pivotal trial will evaluate the safety and effectiveness of the Nanostim and will enroll approximately 670 patients at 50 centers in
Even with a smaller battery, the device is expected to have a battery life span of more than nine years at 100 percent pacing and more than 13 years at 50 percent pacing.
Nanostim was approved for sale in
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