- A heart condition leaving people feeling dizzy may develop in Covid patients
- Known as POTS, it is a condition that causes dizziness when standing up
- Doctors examined the cases of three Swedish patients who developed the condition after testing positive for coronavirus in spring 2020 A rare heart condition that leaves the sufferer feeling dizzy or causing them to faint 'could be a long-term effect of Covid-19', scientists have warned.
Doctors from Lund University examined patients diagnosed with Covid-19 that developed postural orthostatic tachycardia syndrome (POTS) months later.
POTS is a condition most commonly known for causing dizziness upon standing, but symptoms can include palpitations, headache, fatigue and blurred vision.
Causes of POTS are usually undetermined, but it can be precipitated by viral illness, severe infection or trauma and the Swedish team have now seen it after Covid-19.
So far 200 to 250 people have been diagnosed with POTS following a Covid-19 infection in Stockholm, Sweden - where the study was conducted. There is no data available on the condition for other places.
This suggests that POTS could be a 'long-haul' symptom of the disease that has put much of the world in lockdown, the study authors said.
Lead author Madeleine Johansson told MailOnline the 'long-term prognosis is yet unknown but some patients recover spontaneously after 6-9 months,' althought, she added that 'others have yet to recover from the condition.'
There is no cure or standard treatment, but it can be managed with self-care and some medications, according to the doctors behind the new study.
The patients examined by the researchers showed Covid-19 symptoms but not all of them had to seek medical help or had a coronavirus test to confirm the infection.
All three patients began experiencing symptoms of POTS about three months after suspected infection, including extreme fatigue, headache, nausea and dizziness.
POTS was confirmed using active standing and head-up tilt tests.
'As reports of COVID-19 patients being impacted by long-term symptoms unrelated to their original diagnosis continue to grow, it's important to raise awareness of POTS as a possible long-term complication,' said Johansson.
'Much remains unknown about the specific mechanisms responsible for the POTS-like symptoms in post-COVID-19 patients or how long these symptoms will last.
'But chronic symptoms are expected in a subset of patients based on this initial clinical experience.'
The researchers note that a negative Covid-19 test does not exclude the patient from having been infected with Covid-19.They said that based on these findings a negative test 'ought to be interpreted with caution in the context of typical symptoms.'
In addition, other causes of POTS-like symptoms should be excluded, including dehydration, other infections, anxiety and anemia before diagnosing a patient with Covid-19-related POTS.
'It is estimated that 5-10% of all younger women get sick in POTS,' generally, not just related to Covid, Dr Johansson told MailOnline.
'So far between 200-250 individuals have been diagnosed with POTS following COVID-19 infection in Stockholm, Sweden,' where data has been gathered.
'We receive new referrals every week on patients newly diagnosed with POTS after COVID-19,' she added.
About 25-50% of patients go on to recover spontaneously after 6-9 months of developing the condition although there is no public data on this, she said.
'Regarding long-term prognosis, there are patients who have not recovered in over a year since being diagnosed.'
According to the NHS, if someone has the condition, when they sit up or stand, gravity pulls some of the blood down to their belly area, hands and feet.
'In response, your blood vessels quickly narrow and your heart rate increases slightly to maintain blood flow to the heart and brain, and prevent blood pressure dropping.
'This is all done without needing to think about it, by the autonomic nervous system – the nervous system in charge of automatic body functions,' the NHS wrote.
PoTS is diagnosed if your heart rate increases by 30 beats a minute (bpm) or more (40bpm in those aged 12 to 19) usually within 10 minutes of standing and continues for more than 30 seconds.
Doctors can detect the condition through a tilt table test, active stand test, ECG and 24 hour ambulatory blood pressure and heart rate monitoring.
The report didn't make clear how many people had been diagnosed with POTS after developing Covid-19 as it focused on a case study of three patients.
This is the latest in a number of conditions associated with Covid-19 that develop after the initial symptoms have subsided.
This included a rare hyperinflammation condition known as MIS-C that develops in children and can show as a rash.
The findings have been published in the journal JACC: Case Reports.