The last time doctors tried the operation in this country was nearly a decade ago. Andrea Cambern from CBS News affiliate WBNS in Columbus, Ohio
The operation involved two babies in the same intensive care unit at the Columbus Children's Hospital. One needed a new heart the size of a walnut. The other needed new lungs the size of butterfly wings.
Four-month-old Jason Wolfe had developed pulmonary hypertension. His lungs were dying.
"We thought we were going to lose our son and we told the doctors at the time that, you know, if anything happened to him, we wanted him to be an organ donor, you know, to help somebody else out," said Mike Wolfe, Jason's father.
Kayla Richardson, age three months, was born six weeks prematurely. The right side of her heart didn't develop properly. She was put on a heart-lung machine to keep her alive.
Both sets of parents were told their children would die without a transplant.
"We're a spiritual couple and we pray a lot, but we didn't know how to pray for that because it would mean that someone's child would have to pass for our child to survive," said Robert Richardson, Kayla's father.