Nicole Field vividly recalls the morning she woke to find she couldn't breathe properly.
"I'd try to take in a deep breath, and it would catch halfway," the Hamilton woman said of the day, almost 20 years ago, that changed her life forever.
Worried about having developed asthma, she immediately saw a doctor.
"He said there doesn't seem to be anything wrong with your lungs as such, but your heart rate is going incredibly high."
After a round of tests, she was diagnosed with heart failure.
"It's a pretty staggering ... phrase, isn't it? I was just flabbergasted, really, because I had never even entertained the notion that the problem that was going on was a heart issue, and then the word failure is fairly big, as well."
What caused it was a mystery - and for the next 15 years, Field went about her life cautiously, with drugs to help take the workload off her heart.
But things took a turn for the worse when, soon after getting married in Las Vegas, her body began to shut down.
"I was hospitalised fairly quickly when we got back to New Zealand . . . my medical team told me drug therapy wasn't really going to be able to cut the mustard any more in terms of keeping me going," said Field, speaking to the Herald for World Heart Day.
"The only option I really had left was a heart transplant, if I could get accepted for that."
At this point, Field was "incredibly sick" - she constantly felt weak, exhausted and even getting out of bed was a struggle - and her life expectancy was estimated at less than two years.
With a mechanical device having to be implanted in her heart, she was warned that if she got any sicker, she'd have to be removed from the heart transplant waiting list.
But after a year of waiting, she finally got the call she'd been waiting for.
"[My heart transplant co-ordinator] said to me, 'what are you doing?' and I said, 'I've just had a cup of tea', and she said, 'well, finish your cup of tea, and after that, I don't want you to eat anything, and you better start packing your bag and getting up here, because we think we might have the perfect heart for you."
A day later, Field had a new heart - but she was far from out of the woods.
Complications meant she was kept in a coma for a month after the operation, and required further surgery on her lung.
She said it took her the best part of the year before things started levelling out; but eventually, she got her life back.
"Every day I'm grateful because of the decision that somebody in somebody else's family made, and I think that unless you're an organ recipient yourself, you'll never really get it."
Field's story is all the more poignant today, as New Zealand lights up the Sky Tower to acknowledge the 6000 lives lost each year to heart disease in this country.
The Sky Tower will not only beam red, it will pulsate for hearts around the world, igniting the flame for other famous landmarks and cities taking part, including Shanghai, Geneva and Cape Town.
Heart Foundation medical director Gerry Devlin said World Heart Day was the biggest international platform for raising urgent awareness around cardio-vascular disease (CVD).
"CVD, including heart disease and stroke, is still the number one cause of death worldwide, claiming 17.5 million lives per year, while remaining the number one killer in New Zealand."
The Heart Foundation is using the day to promote prevention as a way to stop New Zealanders dying prematurely of heart disease.
"Lifestyle factors continue to be a core focus for the Heart Foundation, with fresh and ongoing evidence stacking up against the Kiwi diet and our nutritional environment."
A recent report from the Ministry of Health points to dietary risks, such as low fruit and vegetable consumption, as the leading cause of health loss, now overtaking smoking as the most dangerous risk.
"The fact that diet and BMI are leading causes of health loss is extremely concerning," Devlin said.
"It reiterates what we've known for quite some time. That we have an obesogenic food supply and we're just not doing the basics right, such as eating mainly whole and less processed foods, which includes plenty of fruits and vegetables."
Also marking World Heart Day are Life and Unichem pharmacies, offering free in-store blood pressure checks in all stores around the country today and tomorrow.
Devlin said people could maintain heart health by visiting GPs for a heart check, recommending checks for men from 45 and women from 55.
To find out more about organ donations, visit the Organ Donation New Zealand website.
For heart health advice or how to donate towards our life-saving research, visit the Heart Foundation website.