Doctors in Australia have transplanted a 'dead' heart that stopped beating for 20 minutes. It's being described as the biggest heart transplant breakthrough in a decade, one that could revolutionize the way organs are donated. The technique, which utilizes a portable unit that keeps blood flowing through heart tissue, took 12 years to develop. Previously, transplant units relied solely on donor hearts from brain dead patients whose hearts were still beating.

Image: St. Vincent's Hospital Heart Lung Transplant Unit/MacDonald et al.