Pacemakers save lives, but as with any medical devices, there are risks, including infection and hacking from malicious outsiders (less likely, but still). Cardiologists at the Cedars-Sinai Heart Institute have come up with an alternative that requires no external device. Using heart muscle cells, they have essentially created a biological pacemaker.
The work, recently reported in the journal Science Translational Medicine, is the culmination of over a decade of research that could help the 300,000 people who get pacemakers each year in the U.S.
Electronic pacemakers send electrical pulses to the heart every time it misses a beat or beats slowly. In healthy hearts, the body creates its own pacemaker cells that act like a metronome, located in the heart’s sino-atrial node. These cells fail in people who require electronic pacemakers.
The researchers have figured out how to turn an area of heart tissue not normally responsible for starting heartbeats into pacemaker cells. Eduardo Marbán and his colleagues injected a gene called TBX18–which expresses a protein that helps the heart keep rhythm–into the hearts of pigs with a condition called heart block. The injection converted normal pig heart cells into the metronome-like sino-atrial node cells. For the length of the 14-day study, pigs given the TBX18 gene had faster, stronger heartbeats.
The injection gave the pigs working biological pacemakers, in other words.
“We have been able, for the first time, to create a biological pacemaker using minimally invasive methods and to show that the biological pacemaker supports the demands of daily life,” said Marbán in a statement. “We also are the first to reprogram a heart cell in a living animal in order to effectively cure a disease.”
The next step is human trials. They could begin as soon as three years from now.