POTS identified in nearly two-thirds of Long COVID patients

Dizziness, fatigue, brain fog and a racing heart. They're commonly associated with Long COVID, but new Adelaide University research suggests that for some people, these symptoms may also be indications of Postural orthostatic tachycardia syndrome (POTS), a debilitating and difficult-to-diagnose condition.

Conducted in partnership with SAHMRI, the study compared heart rate changes, symptoms and immune profiles among people with POTS, Long COVID and healthy participants, finding that almost two-thirds (62.5%) of the Long COVID participants also met the diagnostic criteria for POTS.

It's an important finding that could help explain some of the symptoms experienced by people with Long COVID and importantly help clinicians better diagnose, assess and treat POTS.

Published in the Journal of the American Heart Association, the study is believed to be the first to look at autonomic symptoms, heart rate response, inflammatory markers and autoantibodies in people with Long COVID, POTS as well as healthy volunteers.

Specifically, the study showed that on standing, average heart rates rose by 46 beats per minute in the POTS group and 35 beats per minute in the Long COVID group, compared with just 13 beats per minute in healthy volunteers.

In Australia, around 800,000 people are living with POTS. It is a complex and often misunderstood condition affecting the system that controls automatic body functions such as heart rate, breathing and digestion. This can cause a wide range of seemingly unrelated symptoms, making the condition challenging to diagnose.

Lead researcher Dr Marie-Claire Seeley from the Rosemary Bryant AO Research Centre at Adelaide University said the findings could have important implications for how people with Long COVID are assessed and treated.

"What's striking in this study is just how similar the two groups were. Almost two-thirds of the people with Long COVID we studied met the diagnostic criteria for POTS," Dr Seeley said.

"For people living with Long COVID, symptoms such as dizziness, fatigue, brain fog and a racing heart can be debilitating. Our findings suggest that in some cases, POTS may be contributing to those symptoms.

"POTS can be assessed using a relatively simple standing test, so recognising the signs is important. But because its symptoms overlap with other conditions, it can be challenging to diagnose.

"Recognising the overlap between Long COVID and POTS gives clinicians another avenue to investigate it, and identifying POTS earlier could help patients access more targeted treatment and support."

Researchers also uncovered early clues about the biology behind POTS, with blood tests revealing subtle differences in inflammatory markers that suggest low-grade inflammation may play a role.

The impact of POTS and Long COVID on everyday life was significant. Almost six in 10 (58.3%) Long COVID participants had been unable to return to work following their infection, while just 4.2% of participants with POTS were engaged in full-time work or education.

"These are conditions that can have an enormous impact on people's ability to work, socialise and participate in everyday life," Dr Seeley said.

"Better recognition and earlier diagnosis could make a real difference for people living with debilitating symptoms, helping them access more targeted treatment and support."