Heatwaves Strike At The Heart And Claim More Lives Than Any Other Natural Disaster

As ambulances and hospitals grapple with an influx of heart disease patients, a leading cardiologist says heatwaves claim more lives than any other natural disaster.

On Thursday, Adelaide recorded it's hottest day on record. On Friday Melbourne is set to reach mid-40s.

Heatwaves are becoming hotter, longer and more frequent -- and the number of record hot days in Australia has doubled in the past 50 years.

Hospitals around the country are also feeling the heat. Heatstroke is being mistaken for heart attacks, and experts are warning Australians to be vigilant, and aware of heart attack symptoms.

"My ambulance colleagues here in Queensland have told me this summer they have seen a lot of people who think they have heatstroke and it turns out they've had a heart attack," Rachelle Foreman, Director of Support and Care Heart Foundation Australia told 10 daily.

Foreman says while the hospital admission data will take time to collate, "in Queensland we are definitely hearing there have been more heart attacks this summer."

A beachgoer sunbathes on Glenelg beach in Adelaide.  IMAGE: Getty Images.

Executive Director of the Victor Chang Cardiac Research Institute, Professor Bob Graham says there's growing research and evidence of how heatwaves increase the rate and severity of heart attacks.

"Let's not forget that heatwaves claim more lives than any other natural disaster. It's a big contributor to heart disease deaths in Australia," he said.

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Heatwaves kill more Australians than bushfires and cyclones, and a 2014 report found the rate of heart disease deaths is likely to be under-reported.

The study examined 167 years of natural disasters in Australia and found that "heat-related fatalities most often refer to the exacerbation of pre-existing medical conditions such as heart disease or stroke.

"Such deaths are generally recorded officially under that medical condition, resulting in an underestimation of heat-associated mortality."

IMAGE: Getty Images

A spokesperson from NSW Heath told 10 daily hospital admissions for heart attacks this summer require statistical analysis before any heatwave conclusions can be made.

"[Previous] research conducted in NSW has found that a three day period of hot weather (above the 95th percentile maximum temperature) is associated with an 11 percent increase in the risk of dying from cardiovascular disease," the spokesperson said.

In 2009, the extreme heatwave in South Australia dramatically increased the death rate. Researchers found there was a 14-fold increase in direct heat-related hospitalisation in metropolitan Adelaide.

Total cardiac-related ambulance call-outs increased by almost 10 percent in 2008 and 12.7 percent in 2009 respectively.

"In Adelaide, where there are record temperatures, even people with no history of heart disease need to be careful. Dehydration and blood pressure dropping places enormous pressure on the heart," Graham said.

A 2018 Canadian study published in the Heart journal found a nine percent increase in hospitalisations for coronary heart disease (CHD) and stroke in extremely hot weather.

"Monitor fluid intake. People need to be really careful and monitor how much they are drinking and also how much fluid they are losing. People often don't realise how much fluid they are losing by sweating," Graham said.

If you have a heart condition, experts say you need to stay hydrated and keep cool.  This includes staying out of direct sunlight.

"People who already have heart disease or people on diuretics, and older people who may have blocked arteries they don't know about, are most at risk," Foreman said.

Graham says even those without a history of heart disease, need to look out for heart attack symptoms which can present similarly to heatstroke.

  • Pressure, tightness or pain in the chest and arms which may spread to the neck, jaw or back
  • Nausea
  • Indigestion or heartburn
  • Cold sweat
  • Fatigue
  • Light-headedness or sudden dizziness

"People often think that if they are clammy, sweaty and nauseous they are just hot and bothered and are reluctant to call an ambulance.

"Don't delay, don't see a GP even if you think it's heatstroke, call an ambulance. Time is critical, time is heart muscle," Foreman said.

Featured Image: Getty Images

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