Researchers Aim to Use Light — Not Electric Jolts — to Correct Arrhythmias
Treatment seen as gentler alternative to defibrillators (August 28)
When a beating heart slips into an irregular, life-threatening rhythm, the treatment is well known: deliver a burst of electric current from a pacemaker or defibrillator. But because the electricity itself can cause pain, tissue damage, and other serious side effects, researchers at Johns Hopkins and Stony Brook universities want to replace these jolts with a kinder, gentler remedy: light.
In a paper published online in Nature Communications, the investigators describe their plan to use biological laboratory data and an intricate computer model to devise a better way to heal ailing hearts. Other scientists are already using light-sensitive cells to control certain activities in the brain. The Johns Hopkins–Stony Brook researchers say they plan to give this technique a cardiac twist so that doctors in the near future will be able to use low-energy light to treat serious heart problems, such as arrhythmia.
To achieve this, the team is diving into the field of optogenetics, which is only about a decade old. Pioneered by scientists at Stanford, optogenetics refers to the insertion of light-responsive proteins called opsins into cells. When exposed to light, these proteins become tiny portals within the target cells, allowing a stream of ions — an electric charge — to pass through. Early researchers have begun using this tactic to control the bioelectric behavior of certain brain cells, forming a first step toward treating psychiatric disorders with light.
The researchers will use a computer model to conduct virtual experiments. They will try to determine how to position and control the light-sensitive cells to help the heart maintain a healthy rhythm and pumping activity. They will also try to gauge how much light is needed to activate the healing process. The overall goal is to use the computer model to push the research closer to the day when doctors can begin treating their heart patients with gentle light beams. The researchers say it could happen within a decade.
After the technology is honed through the computer modeling tests, it could be incorporated into light-based pacemakers and defibrillators, the researchers say.
Source: Johns Hopkins; August 28, 2013.