(ABC News) -- Four years ago, Joe Quigley got the call that his 6-year-old daughter, Olivia, had suddenly collapsed at East Boston Central Catholic School after doing gym class warm-ups, running around playing ball with her first-grade classmates.
"You dread getting that phone call from the school. I remember every word," said Quigley, a 52-year-old stay-at-home father by day and a bartender by night. "I knew it wasn't just that she fell over and hurt her leg. It was something serious."
When Quigley arrived at the school, Olivia was lying on the floor surrounded by EMTs. He said the little girl, who had never been ill beyond the "usual coughs and colds," had suffered sudden cardiac arrest.
"At that point, she wasn't even stable enough to be moved," he said. "Initially, we were going to Children's Hospital, but they said this child wouldn't make it that far."
Olivia, who is now 10, survived because her school had a medical emergency response plan, and two teachers had rushed to her side to administer CPR.
The little girl has a healthy heart, but its electrical system is defective. She has catecholaminergic polymorphic ventricular tachycardia or CPVT, which can trigger cardiac arrest.
"It can happen again at any time," said Quigley, who lives with his wife Cathy, Olivia, and a 16-year-old son Alex in Winthrop, Mass. "All you can do is be prepared for it."
CPVT is characterized by episodes of fainting without having any structural deformities of the heart, according to Dr. Michael Gewitz, head of cardiology at Maria Fareri Children's Hospital at Westchester Medical Center in Valhalla, N.Y.
"A lot of kids faint at one time in their life," said Gewitz. "The key is if they faint in the midst of either exercise or severe mental stress."
The underlying cause is the onset of fast ventricular tachychardia or arrhythmia. Spontaneous recovery may occur when the arrhythmia stops or it can degenerate into sudden death if cardiopulmonary resuscitation is not readily available.
According to the National Institutes of Health, CPVT is "highly lethal," causing death in 30 percent of all individuals who have had at least one episode and 80 percent of those who have had more spells.
Last year, Massachusetts Gov. Deval Patrick signed a law that requires all schools to have medical emergency response plans. An estimated 250,000 Americans die each year of sudden cardiac arrest in schools, public places and at home. About 10 percent of all these events occur among people under the age of 40.
It took six minutes before the EMTs arrived with a defibrillator and were able to revive Olivia, according to her father. His wife joined him at the emergency room at Massachusetts General Hospital, where their daughter went into cardiac arrest again.
"I was basically pushing the gurney on one side, and my wife was running behind when a nurse was doing chest compressions on her," said Quigley.
Olivia was stabilized on life support in intensive care.
"Eventually, they took her off, but at that point they didn't know what her functioning would be," he said. "They didn't even know if she would breathe for herself. She did."
Olivia had been deprived of oxygen for six to seven minutes, starving her brain and her vital organs of oxygen. She had initial problems with her short-term memory and was barely able to walk.
"She had to learn everything again," she her father. "She couldn't even read anymore. It was like starting again from being a baby."
Except for a few lingering deficits, Olivia is nearly back to normal. She wears an implantable cardioconverter defibrillator (IDC) to keep track of her heart rhythm and to automatically shock it back if she goes into cardiac arrest. She also takes beta blockers.
Olivia's parents had genetic testing for 10 of the top conditions that contribute to sudden cardiac arrest and all came back negative.
"There are so many disorders that can cause cardiac arrest in young children that testing for all of them was like looking for a needle in a haystack," he said. "We knew she was getting the right treatment."
Doctors have told the Quigleys that Olivia randomly mutated the gene that had caused her CPVT. "Our concern was if she had a genetic disorder, it could have passed on to our son," he said.
Olivia still has arrhythmias, but she is not often aware of them happening.
"Sometimes in gym, she'll say, 'I'll need to sit this one out,' when her heart is racing a bit or she is feeling a little faint. But it doesn't happen very often," said Quigley.
The ICD corrects it.
"She is getting the word out that school staff should be trained in CPR, and schools should have AEDs and an emergency medical response plan," said Quigley. "She's putting herself out there."
Summers, she attends an annual camp for others with heart disease.
"That was huge for her," said her father. "All the kids were the same and they were comparing scars."
Olivia and her parents deal with her medical issues in different ways.
"Initially, you just want your child to be well -- you want her to survive," said Quigley. "Now she's survived, where do we go from here?"
The first year, Olivia had nine medical appointments a week.
"That kept you busy and you felt you were doing something, running around here and there," he said. "As that dwindles away, how do you get back to what is normal for your family?"
Now they are active in getting schools to prepare for an event like Olivia's.
"I was completely unaware that her school had a plan," said Quigley. "It's not something I thought to ask, but I am so thankful they did."
Quigley recently attend a conference in Texas for parents of children who had suffered from cardiac arrest.
"It was a huge room and the room was packed. Ninety percent of them had lost a child," he said. "Cardiac arrest isn't rare, survival is."