After frequent visits there was still no diagnosis so the 39-year-old was sent to Waikato for an angiogram.
"This medical officer comes in and says, 'You need a triple bypass. You have three blocked arteries," Dianne said.
Dianne owns a Gisborne gym where she is a trainer. She represented New Zealand in touch rugby, played premier club netball, and competed in CrossFit and bodybuilding.
"Are you sure you have the right person?" she asked the medical officer.
Fearing for her life, she was reassured the surgery was straightforward and performed successfully thousands of times.
The surgery was booked for September 2020, two months before her planned wedding to Reweti.
"I just lost it, because at that time - in two months' time - we would be getting married and all I could think about was, 'Oh my God, they are going to cut me open'," Dianne said.
The night before surgery the family enjoyed a meal together and were in good spirits.
"Don't you dare turn off my life support," she joked to her fiancé before being wheeled into the operating theatre.
Reweti said he immediately knew something was wrong when he answered his phone at 2.30am.
"The voice on the other end made your stomach churn because they too were speaking in a broken voice," he said.
The surgeon later told Dianne there had been life-threatening complications when the triple bypass hadn't worked.
"He said, 'As soon as we opened you up and we touched your heart, it just went boom. It spasmed so hard that we've never ever seen anything like it'.
The surgeons then attempted a quadruple bypass, using an artery from Dianne's thigh, which was also unsuccessful.
"He said, 'You arrested three times on the table, two small ones and one big one that I had to reach in and manually pump. We didn't know what to do'."
With Dianne given one hour to live, the family was told to say their final goodbyes.
Reweti prepared their sons, Inatiaus, 10, and Te Awa, 6, to see their mother.
"I put it on the line that mum is extremely close to dying," he said.
"Naish was all tears and everything, but Te Awa wouldn't move.
"He was just there [in the room]: 'Love you Mum, love you Mum, love you Mum'.
When the hour passed Dianne was still holding on.
After four hours doctors decided to move Dianne to Auckland Hospital by helicopter, her chest still open.
She underwent three more surgeries in Auckland and was in a coma on life support.
The family was told if she did wake up she may not be able to walk, talk, or remember anything.
While her body fought to stay alive, her mind also fought a terrifying battle.
"I was seeing things like they were real," she said.
"I could see myself dead in a box, looking down.
"It was like watching TV and you are flicking from one episode to the next.
"I was hovering above Te Poho-o-Rawiri Marae.
"I could see all the people gathering for my tangi.
"They were waiting for my body to arrive, but no body was coming.
"And that's when I thought maybe I'm going to be alright."
She tried to send signals from her coma to her family, to let them know she was still there.
She remembers hearing her boys talking to her.
"Te Awa was saying, 'I love you, Mumma'.
"Naish going, 'Fight Mum, fight'.
"Man, I fought the hardest fight for them," Dianne said.
Nine days after the surgery she woke up, but the challenges kept coming.
She couldn't sleep "because I'm seeing stuff".
"It was like I was in this picture theatre and all these pictures were going around and around above my head.
"They scared me. I didn't know if they were real or not."
She had to relearn eating, talking and walking.
She was unprepared for her first shower.
"I didn't know whether to laugh or cry. My whole chest was like purple, holes everywhere, just ugly.
"Laugh - because you actually pulled through this surgery – or cry - because you look fricking ugly," Dianne said.
Less than a month after surgery Dianne was discharged to her Gisborne home.
Still unable to sleep, she was worried about protecting her family.
Noise around the house would have her checking every door and window to make sure it was locked, keeping her sons safe.
With the help of counselors and psychologists, she has improved her sleeping patterns and worked through coma memories.
Dianne originally kept her surgery quiet but when the Gisborne community found out she was in a coma messages poured in.
"The few words that most people said were, 'If anyone can do it, you can'.
"I had two boys and they need me.
"I wasn't ready to go, I wasn't going without a fight."
Dianne returned to her gym 10 weeks after leaving Waikato Hospital and three months later danced in Gisborne's Dancing for Life Education fundraiser.
She placed second with close friend Matai Smith and won the People's Choice award.
It is now 16 months since the surgery and she will need to take medication for the rest of her life.
The couple said there was still another bombshell for them, learning surgery could have been avoided.
"They could have treated me with medication. They just didn't know it at the time.
"As you can imagine all the emotions hit home that day - anger mainly, closely followed by heartbreak.
"Broken because I had left my boys for so long - almost for good - and they had to experience all this trauma."
Dianne said she accepts what happened and doesn't lay blame.
"I'm a very rare case and they just didn't know at the time."
After everything that happened, the couple say every day is a blessing.
On January 15, after multiple postponements because of surgery and Covid 19, they finally married surrounded by friends and family.
• Video animation by Te Wai Fairlie.
