The transplant of a dying two-month-old baby's heart did not go ahead at a Toronto hospital Tuesday.

Two-month-old Kaylee has a fatal brain condition called Joubert Syndrome, which has caused a malformation of her brain, leaving her unable to breathe without a machine when she sleeps.

With no way to save their child's life and not wanting to see her suffer any longer, Kaylee's parents, Jason Wallace and Crystal Vitelli, wanted to take her off life support and donate her heart to another baby in need.

They thought Tuesday would be their last day with their daughter.

Wallace said that Kaylee was expected to fall asleep in the operating room Tuesday evening and then be taken off life support. If she died within two hours, her heart would be removed for a transplant.

But doctors called off the surgery when she did not fall asleep as thought.

Wallace said he wants doctors to try again.

"If she's going to die, we got to keep trying," he said. "I want my child to pass on because she can't survive, and to save that child."

Dr. Jim Wright, chief of surgery at the Hospital for Sick Children, told reporters late Tuesday that Kaylee is no longer a candidate for a heart transplant at this time. He said that is subject to change, however.

"This is our first child and the dreams of the grandparents, the hopes of the future ... have been dashed," Wallace said. "Yet the hopes of another child doing the same thing is what we live on for here."

A complicated medical, ethical problem

Wright told reporters earlier on Tuesday they have a strict protocol to follow in preparing for a transplant such as this, known as a cardiac death donation.

"If legal death occurs, then we will remove the heart and proceed with the transplantation," Wright told reporters Tuesday. He later explained that "legal death" means no heartbeat for five minutes.

"If, however, the baby does not die, then the donation of the heart will not occur. The baby will return to the intensive care unit and the care of the neonatologists."

"As you can appreciate, this is an evolving situation and we will keep you informed."

Kaylee's parents say they were first told that their daughter would likely survive for too long after being removed from life support to allow her heart to be used for a transplant. But on Monday night, officials announced that Kaylee's heart is strong enough that there is a chance it could be used.

Wallace and Vitelli have already decided who they would like to receive their baby's heart. Her name is Lillian O'Connor and she is in the neonatal unit in the floor below Kaylee at SickKids.

Lillian is one month old and suffers from a condition called truncus arteriosus, which leaves her blood short of oxygen. Doctors say without a heart transplant, she can survive only a few more weeks.

Kaylee's parents got in touch with Melanie Bernard and Kevin O'Connor of Prince Edward Island, Lillian's parents, after reading about their daughter in a local newspaper and offered them Kaylee's heart.

Wallace told reporters that he's scared that his daughter may die without being able to help another infant.

"That's what scares us right now," Wallace said Tuesday, his voice cracking. "Losing our daughter's OK, I understand that, but I don't want to lose two."

But SickKids says there is no guarantee the heart will go to Lillian. Deciding who will receive the heart depends on who is at the top of the transplant waiting list, based on their urgent medical need.

SickKids has told Lillian's parents -- along with other parents with children on the transplant waiting list -- that a potential donor may have been found.

Now, the parents must decide whether they want to prepare their infant daughter for surgery for a transplant that may have to be called off. Wallace says he knows the parents of any potential recipient have a very difficult decision to make.

"We will understand, as parents, if they reject it because of the risks, which are very significant - and maybe more significant than we knew," he told reporters earlier Tuesday.

Medical ethicist Kerry Bowman of Mount Sinai hospital in Toronto told CTV Newsnet that hospital officials are following both legal and ethical protocols.

"Obviously they are going to great length to respect protocol," he said Tuesday. "They are respecting two lives here."