Doctors have brought a dead adult heart back to life and transplanted it into a person needing a new organ in what is described as a first for US health experts.
Duke University took the heart from a dead donor whose blood had already stopped circulating.
Usually, this would mean the heart couldn't be used for a transplant. However, surgeons used a pioneering technique to run blood back through the disembodied heart so it would beat again.
The heart then began to function and was successfully transplanted into a patient, a win that could benefit thousands of people waiting for heart transplants.
The successful transplant means more people will be eligible for donation as doctors will be able to beat the clock and keep organs alive outside a body.
Normally, tissue that makes up the heart starts to die shortly after it stops beating, making it unusable.
By the time a heart stops naturally, it's already been running on a low supply of oxygen, that the tissue has been dying before circulatory death could be proclaimed.
But the recent successful surgery is considered a gamechanger.
Video of the surgeons' latest victory was posted to Twitter.
The first human heart transplant was performed in 1967 in South Africa. Less than a year later, Stanford University doctors performed the first heart transplant in the US.
In 2017, 24 heart transplants were performed in New Zealand, the highest number ever.
In 2018, 20 people received heart transplants.
The success rates for transplantation in New Zealand are comparable to the international rates, with 90 per cent of heart transplant recipients surviving more than one year.
Kiwi heart transplant recipients have a 78 per cent survival rate after five years.