By Lemor Abrams

UC DAVIS (CBS13) — Doctors say a simple physical in many cases can reveal underlying issues that could help in sudden-death cases.

Why 12-year-old Aaron Nguyen died on a middle-school basketball court is still undetermined. The seventh-grader collapsed on Friday.

After Nguyen’s death, Dr. Stuart Berger says he’ll be doing a lot more work outside the hospital.

“It breaks my heart. Every time it happens, it breaks my heart,” the head of the pediatric heart center at UC Davis Children’s hospital said.

He’s on a mission to reach schools and youth programs to train teachers and students in CPR, and getting children as young as Nguyen to use automatic external defibrillators, which send electric shocks to the heart.

“I would assume that he had what we call a sudden cardiac arrest,” he said. “There aren’t a lot of other things that can do that to an ostensibly health young man.”

Cardiac arrest is when the heart stops beating abruptly, something rare in children that often occurs with no warning or symptoms.

Coaches performed CPR on Nguyen, but couldn’t revive him.

Berger says the survival rate increases when CPR is performed even sooner.

“We do have good data now where in schools where there are CPR AED programs,” he said. “If you have a witness, cardiac arrest—the survival could be anywhere from 60 to 80 percent.”

Last fall, 8-year-old Karla Vatca of Sacramento survived a cardiac arrest on the playground after two teachers performed CPR and used a defibrillator to shock Karla’s heart.

“It does save lives,” Berger said.

If the problem is money, Berger says all CPR-training costs will be covered by Project Adam. The program started in member of a boy named Adam who passed away in 1999—17 years to the day before Nguyen’s death.

Berger is now pushing for legislation for mandatory CPR training at all California schools.