It was during Shereen Fayers's second trip in two days to her local medical centre that her doctor checked her heart and immediately called an ambulance.
The paramedic arriving at the scene did similar checks and told her: "You're having a heart attack, right now."
By the time the 51-year-old reached Liverpool Hospital, in south-western Sydney, a cardiac team was standing by to find out what was blocking blood flow to her heart.
Recovering in her Leppington home two weeks after the incident, Ms Fayers told the ABC she was amazed how quickly the cardiac team were able to identify and rectify the problem.
What she didn't know at the time was there is a global shortage of a product fundamental to her emergency treatment and long-term prognosis.
Dye in short supply
The issue Ms Fayers initially thought was dizziness and fatigue after fasting through Ramadan, turned out to be a collapsed blood vessel in her heart.
To accurately diagnose her, the team at Liverpool Hospital injected a contrast dye into her blood so X-ray images showed where the blood flow around her heart was blocked.
Cardiologist Dr Sidney Lo then used the images to guide a tiny tube or stent into the blocked vessel to reopen it.
Those images are not possible without the dye — and it's that dye that's in short supply.
"It's vital to the procedure," Dr Lo said. "We can't do it without the X-ray dye."
GE Healthcare is Australia's main supplier of the contrast dye used in medical imaging such as the angiogram Ms Fayers had.
The dye is manufactured in Shanghai. But the factory behind it was forced to shut under a strict lockdown enforced by the Chinese government to stop the spread of COVID-19.
The lockdown lifted this week.
With that one factory out of action and no certainty over when an alternative could be found, Australia's hospitals and radiology practices were last month asked to use the dye sparingly.
One brand, one factory
Dr Lo said before the current supply crisis he had no idea where the dye came from and had not realised how dependent they were on it.
"Suddenly a factory shuts down there and everybody is affected in a big way," he said.
"It's a global problem."
Dr Lo said that at Liverpool Hospital alone as many as 350 potentially life-saving heart operations were performed every year using the contrast dye.
Dr Sanjay Jeganathan, president of the Royal Australia and New Zealand College of Radiologists (RANZCR), said about half of all medical scans performed in Australia used it.
He believed depending on one manufacturer was risky.
He would like to see the federal Health Department consider adding a supply of the contrast dye to the National Medical Stockpile.
The Health Department told the ABC any additions to the stockpile were considered in consultation with the Therapeutic Goods Administration (TGA), and States and Territories.
Pressure eases
The TGA alerted doctors and hospitals across the country when it became clear a global shortage would affect Australian facilities.
Together with RANZCR, they recommended all hospitals and radiologists urgently conserve stock until the situation was resolved.
They issued advice on how to reduce the use of dye, such as by delaying non-urgent scans and using MRI or ultrasound technology where possible.
The agency also gave temporary approval for two other brands of the dye to be used in Australia.
Dr Jeganathan said he thought Australia had done "reasonably well" to manage the shortage and expected the situation to improve in the next couple of weeks.
Push towards self-reliance
The contrast dye is not the only medical product that has run short since COVID-19 put extra demands on the medical system and threw supply chains into disarray.
Other medications in short supply include arthritis medication and some pain killers.
Dr Jeganathan said medical supply shortages were something the federal government needed to watch closely.
When the ABC visited Ms Fayers she was getting back into taking short walks.
Because she was treated so quickly, not only did her doctors save her life, they also prevented long-term damage to her heart tissue, making it easier for her to recover and giving her a better long-term prognosis.
Dr Lo said had his hospital run out of the contrast dye before she arrived, one option would have been to transfer her to another hospital, which would have delayed treatment and possibly caused greater damage to her heart.
He remained concerned the supply crisis wasn't over.
"The crunch is probably coming [as] supplies dwindle a little bit more in the next couple of weeks," he said.
He would like to see Australia look into making its own supply of contrast agents.
"We should be somewhat a bit more self-reliant, less depend on global supply chains, for at least vital medical stuff," he said.
