(CNN) -- On New Year's Day, Windy Hill lay in a hospital bed and described to her doctor the feeling she'd been having.
Her heart, she told him, felt like it was in a vise grip.
Hill described the sensation -- which had come and gone for weeks after she had a baby girl -- like being "punched in the chest."
Yet none of the tests performed on her heart indicated a problem.
"The doctor turned to me and said, 'Seems like she's OK. I think it was just a panic attack,'" said Joseph Berry, Hill's fiancé. "He walked out of the room, was gone four or five minutes and I looked over and she had lost all color in her face."
"She says, 'It's happening again. I'm hurting,'" Berry said.
"I don't remember anything after that," Hill, 38, said recently.
Her doctors suspect that Hill's history of high blood pressure caught up with her, causing the left hemisphere of her heart to buckle and tear, starving a large portion of her heart of blood.
"That whole portion of the heart died," said Dr. Rashid Ahmad, an assistant professor of cardiac surgery at Vanderbilt University Medical Center, where Hill was transferred after her heart attack. "She was teetering on the edge. Her heart wasn't going to recover."
To try to restore blood flow, doctors performed a bypass. When that did not work, Hill was told she needed a transplant.
But because the wait for a matching donor heart could take months, maybe years, doctors offered a temporary solution: a heart pump to keep her alive in the interim.
It was as Hill lay on the operating room table in April -- under anesthesia, ready to receive the pump, tubes and monitoring lines all in place -- that a miracle happened.
"We're prepping for surgery, which means in about 20 minutes I would have made a skin incision," said Ahmad, one of Hill's surgeons. "My cell phone rings and it's the transplant coordinator. A donor heart was identified."
The operating room staff was stunned.
"I've been doing this for about 10 years and this is very rare, a first for me," Ahmad said. "And the timing of it. I could have gotten the call after making the incision, which would have made things much more difficult." With Hill still under anesthesia, Ahmad went to Berry, her fiancé, to deliver the news.
"I told him, the good news is we located a heart," Ahmad said.
But there was a catch: "We want to be really sure this heart won't be immediately rejected."
The odds favored rejection. Windy had just had baby Gracie six months earlier, and antibodies still circulating in her blood would almost certainly attack the donor heart.
But Berry said they had prayed for a heart, and he believed this would be a match.
"I was very excited, holding my breath," he said.
He waited several hours while doctors cross-matched a blood sample from Hill with the new heart, to find out if implanting it would result in rejection.
Against the odds, tests indicated that Hill's body would accept the donor heart.
Later that evening, surgeons implanted the new heart into Hill.
"You know like when you're a kid at Christmas and couldn't wait to see what was under the tree?" said Berry about waiting for Hill to wake up so that he could deliver the good news. "It's like that feeling times a thousand."
Berry was by her side as Hill's eyes tentatively blinked open two days after surgery. He delivered the news that instead of a pump, she had gotten a new heart.
"She just looked at me for a minute. I said 'You hear me?'" said Berry. "She looked at me again, her eyes got real big and she was moving her lips. She said, 'No I didn't.' I said, 'Yes you did.'"
"I didn't believe him at first," said Hill, who then began reaching around to find the pump console. When she could not find it, "That's when I realized I had a heart."
"She looked at me and started crying," Berry said.
Hill had spent a good portion of her daughter's life in the hospital. The new heart, she said, means making up for lost time, getting to know her newborn.
Berry said he owes a debt of gratitude to the organ donor for helping to keep his family intact.
"They gave me and Gracie a second chance with Windy," said an emotional Berry. "Our little girl gets to grow up with her mama. It's a miracle of life."