When these electrical waves go awry, the result is a potentially fatal arrhythmia.
For heart patients, there are currently two options to keep these waves in check — pacemakers or drugs.
However, these methods are relatively crude and they can stop or start waves but cannot provide fine control over the wave speed and direction.
So, the research team set out to find ways to steer the excitation waves, borrowing tools from the developing field of optogenetics, which so far has been used mainly in brain science.
When there is scar tissue in the heart or fibrosis, this can cause part of the wave to slow down.
“That can cause re-entrant waves which spiral back around the tissue, causing the heart to beat much too quickly, which can be fatal. If we can control these spirals, we could prevent that,” explained Gil Bub from Oxford University.
Optogenetics uses genetic modification to alter cells so that they can be activated by light.
A unique protein was delivered to heart cells using gene therapy techniques so that they could be controlled by light.
Then, using a computer-controlled light projector, the team was able to control the speed of the cardiac waves, their direction and even the orientation of spirals in real time.
“The level of precision is reminiscent of what one can do in a computer model, except here it was done in real heart cells, in real time,” noted Emilia Entcheva from Stony Brook University.
In the long run, it might be possible to develop precise treatments for heart conditions.
The results were published in the journal Nature Photonics.