Research Highlights:
- While there are no approved pacemakers for infants in the U.S., a small study found a new miniaturized pacemaker safe and effective for up to two years.
- This pediatric pacemaker may be a viable alternative for newborns who currently receive adult-sized devices, which can create health challenges for the child.
DALLAS, March 3, 2025 — A pacemaker modified for newborns' tiny bodies safely and effectively stabilized their heart rhythms for up to two years, according to new research published in Circulation: Arrhythmia and Electrophysiology, a peer-reviewed journal of the American Heart Association.
Pacemakers are implantable battery-operated devices that help hearts beat in a regular rhythm. Traditional pacemakers, made of a generator, wires (leads) and sensors (electrodes), produce electrical impulses to help control abnormal heartbeats. However, traditional pacemakers are sized for adult bodies.
Study lead author Charles I. Berul, M.D., a pediatric electrophysiologist at Children's National Hospital and professor of pediatrics and bioengineering at George Washington University School of Medicine in Washington, DC, said children comprise about 1% of all patients who need pacemakers.
"There are two challenges with placing a pacemaker in a small child," he said. "First, the device is large compared to the size of a newborn or preemie. Second, the pacing wire from the device to the heart usually goes through a vein in older children and adults. Infants require an open-chest approach so the surgeon can sew on the wire to the heart," he said.
This research fills an important need that could reduce infants' hospital stays, according to Antonio Cabrera, M.D., chair of the American Heart Association's Young Hearts Council. Cabera, who was not involved in this research, is chief of cardiology and co-director of The Heart Center at Nationwide Children's Hospital in Ohio and a professor of pediatrics at the Ohio State University in Columbus.
Infants may need pacemakers when they are born with a rare condition called congenital heart block. In this condition, the electrical impulse doesn't conduct from top to bottom of the heart, leaving these infants with a slow heart rate. The need for treatment with a pacemaker in newborns may also be associated with other rare types of congenital heart defects.
"Newborns and small infants who need urgent pacemaker placement due to congenital or acquired heart block face challenges with limited insertion locations and potential surgical complications and infections," Cabrera said. "With this study's low complication rate and effective pacing, this new device may offer a new alternative for permanent pacemaker placement without the need for temporary leads."
"The need for an urgent permanent pacemaker in newborns is quite rare, but when needed, it is often an emergency," Berul said. "Babies who are very small often cannot get a permanent pacemaker and must undergo multiple temporary pacing wires or other techniques in the hopes of getting them big enough to undergo a standard pacemaker placement."
Researchers studied a pediatric pacemaker about one-quarter the size of full-sized pacemakers — smaller than an AAA battery. Researchers investigated cases at 12 U.S. pediatric hospitals by evaluating 29 newborns and infants who underwent placement of the miniature pacemaker. The babies' median age was 15 days, and their median weight was about 5 pounds. Most of the babies were born prematurely. Some also had congenital heart defects.
The devices were safely implanted and remained stable for an average of 325 days and as long as 2.2 years.
The smaller pacemaker provides a viable alternative to standard-size pacemakers for newborns and could be an option in the future for a larger population of pacemaker recipients. A smaller pacemaker may also help frail elderly patients and be a better choice for some children and adults, Berul said.
"We are working on a small port that would deliver this pacemaker through a straw-sized tool instead of requiring open chest surgery," he said. "This port has been tested in the lab and in small animals."
Study limitations include the small number of participants and limited information on how the device would fare for longer than two years, although by then, the children's bodies may accommodate a standard-size pacemaker.
Berul designed and created the pacemaker's access port and, along with other pediatric cardiologists, consulted with a major medical device company, which developed the pacemaker used in this study. Employees of the medical device company are among the study's authors. Co-authors and authors' disclosures are listed in the manuscript.
