Take a look at this short film made by Dr Nadire Ali at Imperial College London. It shows a cluster of beating heart cells made form embryonic stem cells.
It's a remarkable scientific achievement, and one that has helped convince the British Heart Foundation that regenerative medicine - stem cell technology - could hold the key to mending broken hearts.
The charity, which is already the biggest contributor to medical research into heart disease in the UK, is launching an appeal to raise an extra £50m for stem cell research over the next five years. Money the BHF says could make recovering from a heart attack as simple as repairing a broken bone.
While conventional medical treatments have improved dramatically in recent years, with over 750,000 people now living with heart failure, they're essentially palliative - allowing patients to live with the damage caused by heart disease. Stem cell therapies offer the prospect of repairing that damage, returning the patient to full health.
"We've made great strides in medical research to diagnose and treat people with all kinds of heart problems," says Professor Peter Weissberg, the medical director at the BHF.
Somewhat surprisingly the TV ad promoting the "Mending Broken Hearts" campaign features a talking fish. But this is not just any fish. Along with amphibians the Zebrafish has retained the ability to regenerate damaged heart tissue in adult life.
It's a technique professor Paul Riley at University College London is keen to understand, and exploit. "The whole point of studying the Zebrafish is to understand how it does this, both at a cellular and a molecular level, and to translate that to humans. We want to understand what we need to do try and make a human heart more like a fish heart".
By understanding how the Zebrafish regenerates heart tissue we could learn how to re-awaken the same developmental processes in humans, stimulating the body to heal itself. Then we really would be able to mend a broken heart.