What is POTS, and how is it related to COVID?

I’m reading more and more about POTS, especially in relation to COVID. What is it and what are the symptoms?

A: Postural orthostatic tachycardia syndrome – POTS for short – is a disorder of the “autonomic” nervous system. This system has yin- and yang-like opposing responses: the “fight or flight” side, which gets the heart pounding, and the “rest and digest” side, which tends to more quotidian tasks such as sphincter control when we go to the loo.

When POTS starts, both sides can malfunction, causing blood vessels to dilate. Blood pools in the legs and not enough ascends to the heart, which responds by beating faster. Sufferers get palpitations and feel panicky, while a lack of blood to the brain brings on dizziness, brain fog, even fainting. Welcome to POTS: get it and you’re in for a rough ride.

“I had the exercise tolerance of a 100-year-old,” says Dr Ahmed Bassiouni, an Adelaide-based trainee ear, nose and throat surgeon whose journey began in July 2022 when he got COVID. The sore throat and fever got better quickly; the fatigue didn’t. “I was getting chest pain and shortness of breath climbing one flight of stairs.”

An ECG and heart enzyme test both came back normal. But one day, after operating on a patient, Bassiouni put a probe on his finger, which showed his heart was redlining at 130 beats per minute (the normal resting adult heart rate is 60-100bpm).

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So he scheduled an appointment with Professor Dennis Lau, a heart-rhythm specialist and POTS expert at the Royal Adelaide Hospital. Lau made it official: Bassiouni had POTS and was so disabled by fatigue he had to stop work. “We mount a response to a virus and the nervous system gets attacked by mistake, and then the autonomic control of different bodily functions goes haywire,” says Lau.

Glandular fever and the flu are two established viral illnesses known to trigger POTS; in 2023, they may have been superseded by COVID.

With PhD student Marie-Claire Seeley, Lau is studying the prevalence of POTS in long COVID. They’ve recruited 120 patients and some early, unpublished figures are in. “About 80 per cent of them have POTS or a degree of dysautonomia [dysfunction of the autonomic nervous system], which is staggering,” says Lau.