'Biological pacemaker' tested in lab

Conventional pacemakers are electronic devices that are implanted into the chest to control an abnormal heartbeat. The pacemaker sends regular electrical pulses to keep the heart beating regularly.

Scientists turned heart cells into pacemaker cells by injecting a gene. The "biological pacemaker" was able to "effectively cure a disease", said scientists from the Cedars-Sinai Heart Institute in Los Angeles.

The British Heart Foundation said applications of the research, published in Science Translational Medicine, were "a long way off". The researchers injected a gene into pigs with a heart condition that causes a very slow heart rate. The gene therapy converted some of the billions of ordinary heart muscle cells into much rarer specialized cells that kept the heart beating in rhythm.

The patch of cells the size of a peppercorn had acted as a pacemaker for two weeks, taking over the function of a conventional pacemaker, said the US team.

"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 Dr Eduardo Marban, who led the research team. "We also are the first to reprogram a heart cell in a living animal in order to effectively cure a disease."

Scientists are working on creating biological pacemakers that might one day be used in their place, either as a temporary or more permanent measure. The most amazing pacemaker would be the one that can save baby’s lives; babies still in the womb cannot have a pacemaker, the team is working with foetal medicine specialists to create a life-saving catheter-based treatment for infants diagnosed with congenital heart blockage. "It is possible that one day, we might be able to save lives by replacing hardware with an injection of genes."

Pacemakers had been around since the early 1960s, and while technology was constantly improving, researchers were looking ahead to a day when perhaps an implantable device might not be needed for some patients. However, it is a long way off yet and the benefits of a pacemaker are usually outweighed by the risks.

"Pacemakers continue to be an important treatment for many abnormal heart rhythms, helping to keep hearts beating and save lives."

By Adriana Rueda

Source: Science Translational Medicine

Image: BBC News