Fred Dufour/AFP/Getty Images Electronic pacemakers require invasive surgery to install and carry the risk of infection. Gene therapy could soon join the electronic pacemaker as a treatment for a weak heart. By inserting a specific gene into heart-muscle cells, researchers can restore a normal heart rate in pigs at least temporarily. Electronic pacemakers restore regular function to slowing and arrhythmic hearts by using electricity to stimulate their beating a function usually peformed by the sinoatrial node, a cluster of a few thousand cardiac cells that signal the heart to pump at a regular rate. Although implanted pacemakers are widely used, they require an invasive surgery to be installed, carry the risk of infection, and can set off alarms during airport security checks. To overcome these limitations, a team led by Eduardo Marbn, a cardiologist at Cedars-Sinai Medical Center in Los Angeles, California, sought to coax heart cells outside the sinoatrial node to keep the beat using a less invasive approach. The findings are reported today in Science Translational Medicine1. In 12 pigs, the team mimicked a fatal human heart condition in which electrical activity cannot spread through the heart from the sinoatrial node, forcing other, weaker parts of the heart … Continue reading →

Researchers say they've found a way to transform ordinary pig heart muscle cells into a "biological pacemaker," a feat that might one day lead to the replacement of electronic pacemakers in humans. "Rather than having to undergo implantation with a metallic device that needs to be replaced regularly and can fail or become infected, patients may someday be able to undergo a single gene injection and be cured of slow heart rhythm forever," said senior study author Dr. Eugenio Cingolani, director of the Cedars-Sinai Heart Institute's Cardiogenetics-Familial Arrhythmia Clinic, in Los Angeles. Using gene therapy, the researchers altered a peppercorn-sized area in the heart muscle of pigs to create a new "sino-atrial node" -- the bundle of neurons that normally serves as the heart's natural pacemaker. The technique kept alive a handful of pigs suffering from complete heart block, a condition in which the heart beats very slowly or not at all due to problems in the heart's electrical system. The biological pacemaker also appeared to function as well as an original sino-atrial node and better than typical electronic pacemakers, said study co-author Dr. Eduardo Marban, director of the Cedars-Sinai Heart Institute, in Los Angeles. "When we exercise, our hearts … Continue reading →

NEW YORK, July 16 (UPI) --Pacemakers are one of modern medicine's great inventions. The mechanical timekeeping device essentially salvages failing hearts, saving 3,000 lives every year. Despite their accomplishments, scientists have been looking for an alternative: A way to avoid the invasive surgery -- and the associated risks -- required by traditional pacemakers. A new gene therapy technique suggests humans may be able to just grow their own. While the technique hasn't yet been tested on humans, it has offered promising results in experiments on mice and now, most recently, on pigs. The technique is as follows: scientists inject a gene called TBX18 into heart muscle cells. The gene causes normal heart cells to transform into the type of special cells that dictate the speed of the pumping heart. The genes actually aren't injected directly into the heart, but are loaded onto deactivated cold viruses which infect the heart cells and deliver the new code. "This development heralds a new era in gene therapy, where genes are used not only to correct deficiency disorders but to convert one cell to another to treat disease," said Dr. Eduardo Marban -- director of the Cedars-Sinai Heart Institute, in New York, and author … Continue reading →

Washington No batteries required: Scientists are creating a biological pacemaker by injecting a gene into the hearts of sick pigs that changed ordinary cardiac cells into a special kind that induces a steady heartbeat. The study, published Wednesday, is one step toward developing an alternative to electronic pacemakers that are implanted into 300,000 Americans a year. There are people who desperately need a pacemaker but cant get one safely, said Dr. Eduardo Marban, director of the Cedars-Sinai Heart Institute in Los Angeles, who led the work. This development heralds a new era of gene therapy that one day might offer them an option. Your heartbeat depends on a natural pacemaker, a small cluster of cells its about the size of a peppercorn, Marban says that generates electrical activity. Called the sinoatrial node, it acts like a metronome to keep the heart pulsing at 60 to 100 beats a minute or so, more when youre active. If that node quits working correctly, hooking the heart to an electronic pacemaker works very well for most people. But about 2 percent of recipients develop an infection that requires the pacemaker to be removed for weeks until antibiotics wipe out the germs, Marban said. … Continue reading →