Every year thousands of Americans suffer sudden cardiac arrest.
For many an implantable defibrillator puts the heart's electrical system back in rhythm, life-saving but not perfect.
>> If it discharges, then it's very, very painful and it feels like a horse is kicking you in the chest.
>> When a large electrical shock is delivered, for example, part of the reason why it's so painful Is that it causes all the muscles around the heart to contract.
>> Natalia Trayanova and Patrick Boyle are professors at Johns Hopkins University.
Working with researchers in Baun, Germany, they found another way.
Instead of electricity, they say light may be a better option.
The Baun team tested the theory in animals.
>> They did experiements in mice in which they embedded these light sensitive proteins.
And they did deliver light from the outside of the heart.
And they were able to terminate or defibrillate the heart, terminate the arrhythmia.
>> The Johns Hopkins team then used a computer model of an actual heart to see if a dose of red light would regulate the much larger human organ and it does.
>> The steps that have been done in the last few years are major.
And this is a major milestone.
>> Researchers say someday instead of a major blast to the heart, a gentle light will be all the patient may need.
I'm Malty Sol reporting.