Graphic by Patrick M. Boyle/Johns Hopkins University

Using high-tech human heart models and mouse experiments, scientists at Johns Hopkins and Germany’s University of Bonn have shown that beams of light could replace electric shocks in patients reeling from a deadly heart rhythm disorder.

Current devices deliver pulses of electricity that are extremely painful and can damage heart tissue. Light-based treatment should provide a safer and gentler remedy for patients at high risk of arrhythmia, an irregular heartbeat that can cause sudden cardiac death within minutes. This idea springs from advances in the field of optogenetics, in which light-sensitive proteins are embedded in living tissue, enabling the use of light sources to modify electrical activity in cells.