JACKSONVILLE, Fla. -

Two teenagers from Uganda have received life-saving heart surgery in Jacksonville.

Hospital officials say the girls suffered from a congenital heart defect that causes a low level of oxygen in the blood. Both girls underwent surgery this week at Wolfson Children's Hospital.

One girl is 15 and the other turns 15 on Sunday. The disease often kills children by age 12. Cindy Bonsall, who directs the Children's Heart Project, said the girls had been "living on borrowed time."

Health officials say both girls are recovering nicely.

The Children's Heart Project paid for the trip for the girls, their mothers, a translator and a pediatric nurse from Uganda.