One in three Australians will develop an irregular heartbeat, yet many will have no idea until they suffer a stroke.

NSW women Maryanne Bawden knew she had the condition but took little notice of it.

She had minor surgery a few years back and had some idea that her heart was beating a different rhythm, medically known as Atrial Fibrillation, but was not told how dangerous it could be.

She was told to treat it with Aspirin and wore a wrist monitor to keep on top of it, but it was never monitored properly by a medical professional.

She suffered a stroke and was momentarily paralysed down her left side.

After spending four days in intensive care, Ms Bawden said medical staff told her how fatal her condition was.

"I was warned that I could have been a vegetable for the rest of my life," she told AAP.

In hindsight, she says she wishes she treated her condition more seriously.

"Now I understand all the consequences of AF, you can be short of breath, exhausted and all of those things ... but with the right medication it can save your life," she said.

To celebrate Heart Health Week, one of Australia's leading experts will lead the world's largest screening of AF with and ECG to help prevent stroke.

Professor Ben Freedman, Deputy Director of Cardiovascular Research at the Heart Research Institute and founder of AF-SCREEN International Collaboration, says the number of people in Australia who unknowingly suffer from AF is projected to increase by 150 per cent over the next four decades.

That trend will lead to an increase in stroke and heart failure.

"One in three people aged over 50 will develop AF. The issue is, most people have never heard of it, and that's problematic because it means they don't know to ask their doctor to check for it," he said.

Over the next five years, Professor Freedman and his team will measure AF in Australians aged over 70 using a handheld device, to provide definitive evidence that more intensive ECG screening prevents stroke, morbidity and death.

He said AF is also more common in men than women.

"People can live suffering these small, silent strokes, and they don't even know they are having them. But while they might not notice them, over time they cause a cognitive decline," Professor Freedman said.

"We need to increase awareness of AF, as only 11 per cent of people over the age of 65 are being regularly screened for AF by their GP despite it being a very simple test.

"Almost everyone who turns 65 should be getting a yearly pulse check. Cost isn't a factor - anyone can afford a pulse check."