Studies conducted at Children's Hospital Boston tested the ability of immature skeletal muscle cells to interconnect with heart cells and spread the electrical impulses that keep the heart beating properly.
"The cells have survived in rats for more than a year and they appear to have made connections with cardiac cells," says Douglas B. Cowan, Ph.D., a cell biologist who led the study. "The electrical pathway developed within 10 weeks of implantation.
"Ultimately maybe a decade down the road we may be able to use such cell-based technologies in humans to free them from cardiac pacemaker devices," says Cowan, also an assistant professor of anesthesia at Harvard University Medical School in Boston.
Heart contraction starts with an electrical signal that begins in the atrium, a tiny area of the heart's upper-right chamber. The signal then moves to the other chambers. Damage to the electrical pathway between the atrium and ventricles (the lower chambers) can result in complete heart block, a potentially fatal condition that can only be treated by implanting a cardiac pacemaker.
"We have gathered preliminary evidence that immature skeletal muscle cells can establish a pathway to transmit electrical signals from the heart's upper right chamber to its lower right chamber," he says.
Heart block is present in about one in 22,000 births, Cowan says. It also can result from open-heart surgery in children, or develop later in life. It's particularly difficult to treat in infants and children, he says.
"You can't feed pacemaker wires through the blood vessels of some pediatric patients because the vessels are too small," he explains.