'Miracle' Woman Ruby Graupera-Cassimiro Survives After 45 Minutes Without Pulse New mom revived after rare C-section complication stopped her heart.

 -- Doctors glanced up at the monitors to call the time of death for a patient whose heart hadn't beat in 45 minutes and who hadn't breathed in three hours.

Then, they saw it: a blip on the screen.

Ruby Graupera-Cassimiro was alive.

"She spontaneously resuscitated," Boca Raton Regional Hospital spokesman Thomas Chakurda told ABC News. "We had brought the family in. We had announced to them that we had done all we could."

Graupera-Cassimiro, 40, had gone to the hospital for a cesarean section on Sept. 23. The surgery was uneventful and the baby was healthy, but Graupera-Cassimiro started to experience shortness of breath and doctors had to call a code when she stopped breathing. They tried for three hours to revive her but it was no use. She had no pulse for 45 minutes. Then, her heart started beating again on its own.

Doctors think she had a rare condition called an amniotic fluid embolism, which is what happens when the amniotic fluid leaks into the blood stream, causes blood clots and leads to cardiac arrest, according to Mayo Clinic.

"It's normally diagnosed post mortem," Chakurda said.

He said "extraordinary" doesn't begin to describe what happened. The hospital staff is calling Graupera-Cassimiro's survival a "miracle." Despite having no pulse for 45 minutes, she had no neurological damage, no bruises from the chest compressions, no burn marks from the paddles.

Afterward, Graupera-Cassimiro told her sister that she saw their deceased father and he told her she needed to come back, Chakurda said.

"In a follow-up with one of the physicians, she looked him dead in the eye and said, 'You don't have to be afraid of dying.'" he said.

"I've never seen a group of people so impacted, if you will, by what they saw," Chakurda added. "They all were very struck."

Amniotic fluid embolisms aren't well understood, according to Mayo Clinic.

"It's likely that amniotic fluid contains components that cause an inflammatory reaction and activate clotting in the mother's lungs and blood vessels," according to Mayo Clinic's website.

They can lead to brain damage or even brain death.

"It's estimated that amniotic fluid embolisms cause up to 10 percent of maternal deaths in developed countries," according to Mayo Clinic. "Death can occur within an hour of the start of symptoms."

The rare complication occurs in 1 in 15,200 deliveries in North America, according to the Amniotic Fluid Embolism Foundation.