BRANDON, Wis. — She couldn't bring herself to write the letter. The weight of guilt was too great.

Dawn Revels had wanted to pen some words of gratitude to the family of her heart donor following her June 2017 transplant surgery, but she struggled.

"I mourned and I cried for my donor's family," said the 43-year old Brandon woman. "I had my life back, but they had lost a loved one in the process."

For the time being, she tucked away the thought of a letter and set about getting her life back in order after an ordeal that brought her to the brink of death and back, several times.

She had no way of knowing it then, but she would have a chance to meet and thank the son of the woman who donated her heart so that Revels could live. It wouldn't be because of a letter she sent, but because of a litter of black lab puppies and a chance encounter on Facebook.

Revels' rare, pregnancy-related condition following the birth of her second child 18 years ago left her with a profoundly weakened heart muscle that could no longer meet her body's needs. As a result, her other organs gradually began to fail, said her doctor, Mitchell Saltzberg, medical director of the heart failure and transplant program at Froedtert & the Medical College of Wisconsin.

"Prolonged and acute," was how Saltzberg described Dawn's condition. And over time, just about everything that could began to go wrong.

Leaky heart valves and an enlarged heart led to a four-month hospital stay, and left the mother of two so debilitated just rolling on her side took great effort. Revels' life became a series of medical interventions: kidney dialysis, pacemaker implant, a trach tube to breathe, another tube to deliver food to her stomach. She had to learn to walk again. She used a chalk board to communicate.

As a last resort, to save her life, doctors sent her home in November 2015 — a week before Thanksgiving — with a ventricular assist device. The implanted machine aids in pumping blood through a weakened cardiovascular system and serves as a bridge, Revels said, for people waiting for a new heart to become available.

"I had to be plugged in at all times and I needed a lot help from family," Revels told the Fond du Lac Reporter . "With so many sick people out there and not enough donors, I truly believed a transplant was never going to happen for me."

After living with the device for two years, the part of her heart that still functioned started to go bad and her condition reached critical. She was bumped to the top of the transplant waiting list for 30 days. But a new heart did not become available in that time.

Through a recommendation from her medical team, Revels was bumped to the top of the list a second time.

"It was a difficult time for me and my family. I didn't know how to ask God to provide a heart for me, knowing that someone would lose their life in the process — someone people loved," Revels said.

Within five days she received the long-awaited phone call, and the miracle she and her family had been praying for.

"I posted a picture of myself on Facebook driving to the hospital with my son and husband," Revels said. "I asked for prayers and peace for guidance."

That same day, Dustin Smits' world came crashing down around him, yet again. The 27-year-old race car enthusiast from Friesland seemed to have been dealt a bad hand in life.

In June 2016, his father and best friend Todd Smits died in a car crash, driving the Jeep the two had rebuilt earlier that year.

The car hit some loose gravel and ended up upside down in the ditch. His father died before help could arrive.

Then, on the first anniversary of his father's death, Dustin Smits received a call that his mother Tracy Smits was in the hospital, suffering from a brain aneurysm. She was placed on life support, and Dustin Smits — an only child — was forced to make an emotional decision.

"Doctors said her organs would be able to save others, and I went ahead with it because I knew this was something my mom would have wanted," he said. "Everyone who knew my parents would tell you what giving people they both were."

As if those two blows weren't enough, Dustin Smits' black lab Trigger died that same summer. The beloved pet was only seven years old.

"It was a tough time for him and he had a lot of anger," said Dustin Smits' girlfriend Whitney Schickert. "He and his dad were so close, and he wasn't over his dad's death when his mom died. Within a year and a half, he had literally lost everything."

Since the transplant surgery, Revels' renewed strength had been focused on family and enjoying her young granddaughter. The unexpected arrival in the fall of a litter of puppies from Nelli, the Revels' family dog, added a liveliness to the household.

On Nov. 8, Revels posted on Facebook that the black lab pups were now ready to go to good homes — and, though they didn't know each other, that message caught Schickert's eye. She had been searching on Facebook for puppies. Dustin Smits had told her he didn't want another dog, but she was thinking it might do him some good.

"I started looking at Dawn's Facebook page, just to check her out," Schickert said. "That's when I noticed she had received a heart transplant on the same day Dustin's mother died."

Through an exchange of messages, the two women began to unravel the truth. Revels told Schickert about a letter she had received from her heart donor's mother about six months after the surgery — a woman named Jean.

"I knew the person whose heart I had was named Tracy. I did not know how she had died, only that her husband has passed away a year before her," Revels said.

"I started shaking and crying. I couldn't believe it," Schickert said.

Revels confessed that she hadn't been able to answer the letter. But the feeling of guilt she had been carrying around for a year and a half began to fade as the two made plans for her to meet Dustin Smits.

"When Dustin found out, he took off work the next day. He couldn't wait," Schickert said. "The minute we came through the door of Dawn's house, we all embraced each other."

Schickert brought along a stethoscope, so Dustin Smits could hear his mother's heartbeat.

"It was emotional, it choked me up," Dustin Smits said. "And it blew me away that the person who had my mom's heart lived 25 miles away from us, knew some of the same people."

For Revels, it was a life-changing moment.

"I felt like I had known them forever, like they were long-lost family," she said. "I told Dustin that I know I am not his mom, but I want to be a big part of his life. He said he felt the same way."

The puppy that brought them together, 10-week-old Oaklynn, is growing like a weed. Dustin Smits said she still likes to wake the couple up at night and early in the morning, whining and wagging her tail, looking for attention.

"It's amazing to think that if it wasn't for Trigger dying, Whitney would never have been looking for another puppy and all this would have never happened," Dustin Smits said.

Revels sees the gift of the little black lab as a small thank you, although she knows it will never be enough.

"I feel like our stories have come together for a reason, to help us both heal, and I am forever grateful," she said.

Saltzberg said that since her surgery, Revels has remained a vital part of Froedtert's volunteer program as a mentor to new patients on the transplant list who need to learn how to use the ventricular assist device. She encourages them to be hopeful, and positive about their outcome.

"I feel this is a way I can give back for everything that was done for me, and that includes honoring the heart that was given to me," she said.

Dustin Smits said his mom's heart could not have gone to a better person. Since meeting her, his life feels fuller.

"He is definitely calmer, more at peace," Schickert said. "It was the kind of closure that he needed. And for all of us, it's a celebration of Dawn living and Tracy giving," she said.

Today, there are approximately 3,900 people in the U.S. waiting for a new heart — roughly 10 times the number of people who will actually receive the essential organ to save their life.

"We have an ongoing critical shortage of organs and donations are the only way people like Dawn and others have a chance," Saltzberg said.

An AP Member Exchange shared by the Fond du Lac Reporter.