ST. PETERSBURG - Ask 9-year-old Jayden Langan why he's in the hospital, and he doesn't really know, but his father does.
Will Langan is Jayden's father.
"It scared me to death. It's, I mean, since he had his heart transplant we knew at any time he could go into rejection."
I first met will and Jayden nine years ago, at All Children's Hospital.
It was a night when Jayden's life hung in the balance, with a heart defect doctors couldn't repair. I waited with his parents as a new heart was transplanted and doctors came back with good news.
Since that night, Jayden has been relatively healthy and Dr. Jeffery Jacobs has gone on to transplant more than 100 other hearts into dying children.
"When we put a new heart in a baby, 80 percent are alive and doing well five years later, and probably 7 out of ten are alive and doing well ten years after the transplant," Dr. Jacobs said.
But the fact is, heart transplant surgery is still relatively new and no one knows how long these unique kids will survive.
So when Jayden came in Friday in stage 3 rejection, his parents feared it was life threatening.
Dr. Alfred Asante-Korang is the Medical Director of the Heart Transplant Program at All Children's Hospital.
"If the heart function is severely affected, then it can be life threatening."
Right now, doctors are treating his rejection with medication. They'll do a biopsy of the heart to see if the medicine is working. If not, Dr Jacobs said, "Occasionally after a heart transplant, a baby will need a second or third heart transplant over the course of their life."
"We don't know what the future holds, but we hope that we'll come up with new medications that will keep these kids alive into their 50's and 60's and have kids and grandkids," Dr. Asante-Korang said.
Jayden's dad said, "Every day is a day we might not have had with him, so you just take that day."
To follow Jayden's story go to: http://wfts.tv/16BxgBT