You've had a heart attack. You're wheeled into A&E on a gurney. You survive, but your heart muscle is damaged. It's called heart failure - your heart just doesn't pump properly. Your long-term prospects look none too good.
All that could change if experiments on rats at Kings College on London are shown to hold for human beings too. After a heart attack, you would get an injection of heart stem cells - cells that can repair the damage to your heart muscles.
The stem cells would "home in" on your heart and grow into new muscle - triggering the stem cells already in your heart to leap onto action.
Sounds like science fiction, but Georgina Ellison, one of the Kings College researchers, told me it could be part of regular clinical practice within the next decade.
Everyone has stem cells in their hearts. Their job is to repair the normal wear and tear on your heart muscles by growing into new muscle cells. Trouble is, as you get older, the stem cells don't work as well. So if you have a heart problem like a heart attack or coronary artery disease, the stem cells can't cope.
Rats have heart stem cells too. When the researchers at Kings destroyed the rats' stem cells, they developed heart failure. When they put the stem cells back in, the failed hearts were restored to proper function. The implication for humans is obvious.
But even better you don't have to inject the stem cells directly into the heart for them to work. In humans that would be quite a serious procedure. Instead, the researchers simply injected the stem cells into a vein and they found their own way to the heart and started the repair process.
So if the same technique works in humans, a simple injection could treat heart failure - and might be able to prevent heart failure developing.
There's only one way of finding out if the technique works for us as well as for rats and that's to try it. So researchers in Spain and Belgium will start human trials of the technique early next year. If they're successful, stem cells could be used to treat heart failure before the end of the decade.