After heart transplant, mom hears late infant son's heartbeat in another baby

— -- Four years after Nikita Nash was forced to part with her dying baby, she remarkably heard his heartbeat again in the body of another child.

Nash lost her son Lucas in 2014 when he was only 6 months old.

Incredibly, after the anguish and heartbreak, Nash flew to Tulsa, Oklahoma, and heard a sound she remembered: Lucas's heartbeat.

His heart had been transplanted into a 3-month-old boy named Kolton Carter, who had been diagnosed with a slew of heart defects.

When Nash heard the beats, it was sublime.

"That is an indescribable feeling," she said. "It sounded like it did when I was pregnant with Lucas."

The heart transplant united two mothers with a special kind of bond.

Kolton's mother, Jenney Carter, expressed to Nash how grateful she was now that her son can live on.

Nash said of Carter: "She wrote, 'From the bottom of your sweet angel's heart that beats inside my son's chest, we thank you.'"