It was the kind of hard-luck case that seemed destined to end in heartbreak.

Born with a congenital heart defect, a 13-year-old girl in Mongolia was suffering from severe heart failure. Even worse, she had no place to go for the medical care she desperately needed.

Enter Dr. Allison Cabalka, a Mayo Clinic pediatric cardiologist. As part of a U.S. medical team, she traveled to Mongolia to treat children with heart defects in countries where heart surgical resources are limited or nonexistent.

Cabalka also helped bring the girl to the Mayo Clinic in Rochester, where she underwent surgery.

"It was life-changing," Cabalka said. "She graduated from high school and university training in Mongolia and moved to Istanbul this year to pursue further education."

In January, Cabalka and her husband, Jeff Cabalka, caught up with the young woman in Istanbul, on their way to yet another medical mission assignment.

"We got to see this 23-year-old, beautiful young girl who probably wouldn't have been alive if she hadn't come to the U.S. for heart surgery though the Children's Heart Project," Dr. Cabalka said.

For years, she has traveled the world with the Heart Project, part of Samaritan's Purse International Relief, treating congenital heart defects, which occur in one in 100 children. Jeff also pitches in, entertaining the kids and their parents while they're waiting for the doctors and escorting children back to their home countries after treatment in Rochester.

The Cabalkas' passports reveal the extent of their travels. "We're up to 36 countries," Jeff said. "We always have to get pages added to our books."

Among their destinations: Nepal, Mongolia, Bolivia and Uganda.

Recently, they returned from northern Iraq — where access to patients was difficult, Dr. Cabalka said. Still, her medical team was able to screen patients and perform nonsurgical treatments, which allowed Iraqi children to avoid surgery.

"That was also a very gratifying experience because we were in a country that is completely torn up right now," she said.

Even when she's not globe-trotting, she tries to help from afar. Typically, she receives ultrasound heart scans every week from colleagues in other countries, seeking to consult with her on a diagnosis.

She and her husband say they are driven by their Christian faith to assist as best they can.

"We're very blessed to have many resources to share," she said. "I think we're called to do that."

Seeing the physical and spiritual impact this work has had on the lives of children and families has been its own reward.

"It gives people profound hope," Dr. Cabalka said, "which is what we all need."