It’s a night 10-year-old Kian Wu and his younger brother Grayson said they will never forget.

The brothers were sleeping over their grandmother’s house and had just started watching a movie.

When they looked over to ask her for a snack they saw her unconscious on the couch.

Patti Chatterson, 62, had gone into cardiac arrest.

“We checked her breathing and there was no sign of breathing, we checked her pulse and no sign of heart beat, so my brother and me knew there was something wrong,” said seven-year-old Grayson.

The boys quickly called 911 and the operator walked them through how to perform CPR.

Medavie Health Services shared the 911 call with media. The operator is heard explaining the procedure to Kian.

“Now I want you to pump the heart hard and fast at twice per second and two inches deep. Let the heart come all the way down between pumps,” the operator said in the phone call.

Kian delivered more than 400 compressions until paramedics arrived and took over. Chatterson was rushed to hospital where she later recovered.

“They’re my heroes for life,” Chatterson said.

On Tuesday, Medavie Health Services awarded Kian and Grayson for their heroic efforts. They were each given a Star Award, given to those who go above and beyond to save a person’s life.

“It’s something I never heard before. This is something that is once in a lifetime, in my career of 23 years, that I’ve heard,” Medavie Health Services spokesman Troy Davies said.

As a retired nurse, Chatterson said what happened to her is a “miracle.”

“I’m on my second life now and I’ve gotten a much better appreciation – a renewed appreciation – for life.”

“We’re very lucky that our grandma survived,” Grayson said.