Researchers have developed a wireless, battery-free, fully implantable heart pacing device that dissolves when it is no longer needed.
Developed by researchers at Northwestern and George Washington (GW) universities, the flexible device – which is 250μ thick and weighs under 0.5g – could be used in patients who need temporary pacing after cardiac surgery or while waiting for a permanent pacemaker. All components of the pacemaker are said to be biocompatible and naturally absorb into the body’s biofluids over the course of five to seven weeks.
The device wirelessly harvests energy from an external, remote antenna using near-field communication protocols, which eliminates the need for batteries and rigid hardware, including wires that can introduce infections or become enveloped in scar tissue.
The study, published in Nature Biotechnology, demonstrates the device’s efficacy across a series of large and small animal models.
“Hardware placed in or near the heart creates risks for infection and other complications,” said Northwestern’s John A. Rogers, who led the device’s development. “Our wireless, transient pacemakers overcome key disadvantages of traditional temporary devices by eliminating the need for percutaneous leads for surgical extraction procedures – thereby offering the potential for reduced costs and improved outcomes in patient care. This unusual type of device could represent the future of temporary pacing technology.”
“Sometimes patients only need pacemakers temporarily, perhaps after an open-heart surgery, heart attack or drug overdose,” said Dr. Rishi Arora, a cardiologist at Northwestern Medicine who co-led the study. “After the patient’s heart is stabilised, we can remove the pacemaker. The current standard of care involves inserting a wire, which stays in place for three to seven days. These have potential to become infected or dislodged.”
To set up temporary pacing after open heart surgery, surgeons sew temporary pacemaker electrodes on the heart muscle during surgery. These have leads that exit the front of a patient’s chest, connecting to an external pacing box that delivers a current to control the heart’s rhythm.
When the temporary pacemaker is no longer needed, physicians remove the pacemaker electrodes. Although uncommon, potential complications of implanted temporary pacemakers include torn or damaged tissues, bleeding and blood clots.
Surgeons and patients can avoid this procedure as the soft and flexible implantable device encapsulates electrodes that laminate onto the heart’s surface to deliver an electrical pulse.
“The circuitry is implanted directly on the surface of the heart, and we can activate it remotely,” Arora said in a statement. “Over a period of weeks, this new type of pacemaker ‘dissolves’ or degrades on its own, thereby avoiding the need for physical removal of the pacemaker electrodes. This is potentially a major victory for post-operative patients.
“With further modifications, it eventually may be possible to implant such bioresorbable pacemakers through a vein in the leg or arm,” he added. “In this instance, it also may be possible to provide temporary pacing to patients who have suffered a heart attack or to patients undergoing catheter-based procedures, such as trans-catheter aortic valve replacement.”