The Arizona Republic, David Wallace) MARICOPA COUNTY OUT; MAGS OUT; NO SALES, Associated Press
In this Tuesday, Jan. 17, 2012 photo, Cora Kasten, 4, sits with her mother, Kelly Balsamo as Brandon Ogles, 18-months, sits with his mother, Danielle Chambers at Phoenix Children's Hospital in Phoenix. Brandon, who had his heart transplant Jan. 4, and Cora who had her heart transplant Jan. 10, became friends in the hospital.

PHOENIX — It's an unlikely friendship: an 18-month-old boy nicknamed Bam Bam and a 4-year-old girl who has battled for every breath since birth.

Over the past couple of months, as they both waited for heart transplants at Phoenix Children's Hospital, the two children became fast friends.

Brandon Ogles would climb out of his wagon as he passed Cora Kasten's hospital bed.

Once, when Cora had tears in her eyes, Brandon swiveled his head toward his mom and asked: "What's wrong with Cora?"

More than two weeks ago, when Brandon was resting after his successful heart transplant, Cora stopped by his room to see how her friend was recovering.

Cora knew that her time for a heart transplant was fast approaching. The call came earlier this month: A donor heart had become available.

Following nearly eight hours of surgery, Cora had a new heart and a renewed lease on life.

"She's got a lot of spirit," said Dana Kasten, Cora's father. "That is the only thing that got her to where she is, because she's been through hell."

The pediatric heart transplants are just the third and fourth performed at Phoenix Children's Hospital since the hospital launched its heart-transplant program last year.

Doctors say they are working toward making the program a "center of excellence." Such a designation will give private insurance companies confidence that the hospital is prepared to handle such complicated medical procedures instead of sending children to another hospital out of state.

St. Joseph's Hospital and Medical Center previously served as the region's chief destination for pediatric heart transplants.

St. Joseph's transferred its pediatric services to Phoenix Children's Hospital as part of a strategic alignment between the two hospitals.

"Most of the time, insurance companies want to see five to eight transplants," said Jeffrey Pearl, a cardiothoracic surgeon who operated on both children.

A medical committee assessed both Cora and Brandon and determined they would be ideal candidates for heart transplants.

The committee evaluates each case and determines whether a child would benefit from a transplant, could use alternative therapies in lieu of a transplant, or has other medical conditions that a transplant would not address.

Cora and Brandon both needed new hearts, but their medical conditions were different.

Last August, Brandon was diagnosed with dilated cardiomyopathy, a condition in which the heart becomes weakened and enlarged and cannot effectively pump blood.

The normally energetic boy who devoured macaroni and cheese became reserved, had labored breathing and lost his appetite.

The news of her son's illness was a difficult blow for his mother, Danielle Chambers, who has already dealt with tragedy. When she was seven months pregnant with Brandon, the boy's father, who had the same name as his son, passed away after a bout of bacterial meningitis.

"I felt sick to my stomach," said Chambers, who took a break from her paralegal courses at Phoenix College to care for her son and 5-year-old daughter.

Cora suffers from hypoplastic left heart syndrome. The congenital condition occurs when the left side of the heart does not fully develop. That shifts the burden of pumping blood to the lungs and the body to the right side of the heart.

Within hours of Cora's birth, her pediatrician detected a heart murmur. She was sent by medical helicopter to Phoenix Children's Hospital, where she has been a frequent guest over the past four years.

Her father said she has had five procedures to try to restore function to her heart. Doctors wanted to delay the heart transplant as long as possible. If the surgeons could repair her heart enough to last into her early teens, she could get an adult heart transplant then, which would carry her into her 20s.

For many months last year, Cora lived life just like any young girl. She loved to run. She became a proficient swimmer, attended preschool and even took tap-dance classes.

Then, her energy level began to sap as summer approached. Doctors tried one last heart operation, an experimental procedure performed at a hospital in Milwaukee.

It did not sustain her for long. Her parents, her doctor and a hospital committee charged with making such recommendations all agreed: She needed a heart transplant.

The weeks stretched on past Christmas and New Year's Day. Brandon and Cora spent time with their families and, on occasion, greeted one another in the hallways. Two young children shared the common bond of the need for a new heart.

"They are friends," Chambers said of her son and Cora. "They pass each other's rooms. Brandon jumped out of his wagon trying to get into her room."

Cora's father explained to her last week before her surgery that she was getting a new heart. It would make her feel good and healthy. She could even run after the surgery.

That excited Cora. As the medical staff prepared her for the operation, Cora put on her running shoes.

"She thought, 'I'm going to get a new heart. I'm going to get up, and I'm going to run around,'" her father said.

Doctors say that both Cora and Brandon have recovered well and are expected to be released within a week.

Until then, both children will rest in their hospital beds. Brandon will cuddle up with his mother.

And Cora will be next to her mother and father — with her running shoes on a tray table at the foot of her bed.

Information from: The Arizona Republic,