THURSDAY, July 13, 2023 (American Heart Association News) -- When Jennifer Mayadas-Dering started coughing and having a headache, she didn't think much of it. She was far more concerned with her son, a college freshman who was in the hospital with a lung condition.

From his bedside, she called her doctor. "It's just your asthma," he told her. He prescribed steroids.

Her son recovered, but her coughing grew worse. A competitive racquetball player, she found it increasingly difficult to keep up with her workouts. Her heart rate climbed. She had trouble sleeping because she couldn't breathe when she lay down. Two months and 14 doctor appointments later, Mayadas-Dering had no relief. Things were so dire that she started sleeping upright in a chair.

Her husband insisted they see another doctor to push for answers. This led to an X-ray, which resulted in an immediate trip to the emergency room. Her heart was so enlarged that the doctor couldn't see her lung.

She was soon diagnosed with cardiomyopathy – a disease that weakens the heart and can lead to heart failure, irregular heartbeats and other problems. "The muscle was dying," Mayadas-Dering said. "It was getting bigger and bigger, trying to make up for lost capacity."

While thankful to have found the source of her problems, this answer made little sense to her. At 51, she was in great physical shape, exercising as much as three hours a day before she fell ill. She had no history of heart problems.

Yet the doctors told her she'd need a new heart.

Three weeks later, she was told they'd found "the perfect match."

In Spring Lake, North Carolina, a 28-year-old mother of four named Sarah had just died. Five of her organs were being donated, including her heart.

Losing Sarah was especially tough on her sister, Michelle Johnson, as it came on the heels of losing both of their parents. She had no idea her sister had registered as an organ donor, but soon found herself praying someone would receive her sister's "most precious gift: her heart."

In Westchester, New York, Sarah's heart gave Mayadas-Dering a second chance at life. Physically and emotionally, "my heart and I have bonded so well," she said.

She took long walks during her recovery from the surgery, thinking about her donor. In her head, she composed a letter to the donor's family as she walked and walked and walked.

Meanwhile, in North Carolina, Johnson "waited and waited in the hopes that whoever received it would reach out."

Finally, the day came when Mayadas-Dering was ready to put her thoughts on paper.

She wrote about how she was able to celebrate her 25th wedding anniversary and to see her youngest child graduate from high school – "things I didn't know I would ever be able to do." It was all possible, she wrote, because of "our heart."

Protocol required the letter to go from Mayadas-Dering to donor services to Johnson. In her mind, she believed she was writing to her donor's parents. But it was Johnson who wrote back and explained they had predeceased her sister. She explained that "in the midst of our grief, it helped to know that another family was celebrating."

Donor services told her the heart recipient wanted to meet. Johnson was delighted. They arranged for Mayadas-Dering to come to North Carolina.

But first, with Johnson's permission, Mayadas-Dering mailed a special gift to her donor's children on the anniversary of her transplant. Inside the box were four teddy bears – one for each child. And inside each bear was a recording of Sarah's heart, beating anew in Jennifer's body.

"Hearing that heartbeat, it gave me some kind of peace," Johnson said. When she finally met Mayadas-Dering, she instantly felt a connection.

The women have not only stayed in touch, but a unique friendship has blossomed. They call each other "heart sisters."

They recently met again in New York City for a visit timed to coincide with an event for National Donor Day. Mayadas-Dering picked up Johnson from the airport and introduced her to her family. They saw "The Lion King" and toured the city, including St. Patrick's Cathedral. The celebration coincided with the two-year anniversary of Sarah's lifesaving donation and Mayadas-Dering's transplant.

"We spent time together as what I would call a family," Johnson said. "We had some amazing food and time to get to know each other a little better. Jennifer is an amazing person. I can't think of anyone more perfect for my sister to share her most precious gift with."

American Heart Association News covers heart and brain health. Not all views expressed in this story reflect the official position of the American Heart Association. Copyright is owned or held by the American Heart Association, Inc., and all rights are reserved.

By Laura Williamson, American Heart Association News