US researchers develop first fully-implantable micropacemaker for foetal use

LOS ANGELES: US researchers have developed the first fully implantable micropacemaker designed for use in a foetus with complete heart block.

Congenital heart block is a defect of the heart's electrical system that originates in the developing foetus, greatly slowing the rate of the heart and impacting its ability to pump blood.

Although the condition can be diagnosed in utero, all attempts to treat the condition with a standard pacemaker have failed.

"Up until now, the pacemaker devices that have been used in an attempt to treat this condition in a foetus were designed for adults," said Yaniv Bar-Cohen, pediatric cardiologist at Children's Hospital Los Angeles.

"We have lacked an effective treatment option for foetuses," Bar-Cohen said.

"We now have a pacemaker that can be implanted in utero, potentially without harm to the foetus or the mom," said Ramen H Chmait, Director of the Children's Hospital Los Angeles - University of Southern California Institute for Maternal-Fetal Health.

"This novel device provides a real opportunity to prevent miscarriage and premature birth in babies affected with these abnormalities," Chmait said.

The size of the adult device requires a small part to be implanted in the foetus and the rest to remain externalised. This design has uniformly failed, likely due to foetal movement causing the electrodes to become dislodged from the heart.

"Building on our experience of using microfabrication techniques to create biomedical devices, we have developed a micropacemaker small enough to reside entirely within the foetus," said Gerald E Loeb, professor of Biomedical Engineering at the Viterbi School of Engineering at USC.

"This will allow the foetus to move freely without risk of dislodging the electrodes," Loeb said.

Each year, approximately 500 pregnancies in the US are affected by foetal heart block and could be candidates for receiving this device.

The study was published in the journal Heart Rhythm.