A new advertisement for Toronto's Hospital for Sick Children captures the moment two Ontario parents found out their daughter had survived surgery.

University student Danielle Garand was born with a hole in her heart, but the defect went undiagnosed until high school.

"I noticed that I got tired really quickly and couldn't run very far," Garand told CTV Toronto's Pauline Chan of her childhood. She said she didn't realize it was anything serious until she got older.

Garand was in her last year of high school in the community of Keswick, Ont., approximately 70 kilometres north of Toronto, when she began to feel fatigued all the time.

Garand started to lose weight and went to see a specialist. During the testing, doctors noticed she had a hole in her heart. She was told she had an atrial septal defect, a congenital heart defect in which the wall that separates the upper heart chambers doesn't close completely.

"It was scary... It was just so shocking to know that something was wrong," she said.

"I thought everything was going to be fine."

Garand was told that the hole could be fixed with a surgery at the Hospital for Sick Children (also known as Sick Kids) in Toronto. The surgery was scheduled for October, and Garand started a post-secondary program at Sudbury's Laurentian University.

Garand had the surgery during her Thanksgiving break. She said the procedure was "nerve-wracking," since she'd never had surgery before, but ultimately it was a success.

The moment Garand's parents, Paul and Sandra, found out she'd survived the surgery was captured on camera.

Paul and Sandra Garand are seen hugging in a hospital room, both in tears.

The emotional moment became part of a new ad for the hospital, with the words: "Doctors just repaired a hole in their daughter's heart. And eased the pain in theirs."

Paul Garand said they were elated in the moment shown in the video.

After the surgery, Garand took a two-week break before returning to school. She requires annual checkups for her heart, but is otherwise a normal university student.

She's studying to become a teacher, and said she's looking forward to travelling the world.

With a report from CTV Toronto's Pauline Chan