Research published Monday has confirmed a link between a Covid infection and a debilitating heart condition called POTS, or postural orthostatic tachycardia syndrome, that has been diagnosed in some patients with long Covid.
The findings, published in the journal Nature Cardiovascular Research, are in line with earlier reports from physicians that Covid may trigger POTS, a disorder of the autonomic nervous system often characterized by a rapid heart rate, low blood pressure, fainting and lightheadedness.
Physicians often fail to recognize the condition, experts say, because it can be confused with a myriad of other health problems, including anxiety and dehydration. Many patients spend years trying to get properly diagnosed.
One of the earlier discoveries with long Covid was that it could be associated with POTS and this new research builds on that, said lead study author Dr. Alan Kwan, a cardiologist at Cedars-Sinai Medical Center.
POTS was also linked, to a lesser degree, to Covid vaccination with an mRNA vaccine, according to the new study.
Researchers analyzed data on nearly 300,000 patients from the Cedars-Sinai Health System in Los Angeles County from 2020 to 2022 who had either received at least one dose of a Covid vaccine or had a confirmed case of Covid. The vast majority of the vaccinated people in the study got an mRNA vaccine — either from Pfizer-BioNTech or Moderna. People with a confirmed case of Covid had not been vaccinated.
While the researchers found a small but increased risk of POTS following Covid vaccination and, in particular, the first dose, the risk was greater following a Covid infection itself: Getting Covid was linked to a five times greater risk of POTS than vaccination.
“The main message here is that while we see a potential link between Covid-19 vaccination and POTS, preventing Covid-19 through vaccination is still the best way to reduce your risk of developing POTS,” Kwan said.
He added the study has limitations, including that the results were based on patient data from a single health system. He also said that the link between POTS and Covid vaccination needs to be confirmed with further studies.
It’s unclear why the Covid vaccines would trigger the condition, Kwan said, but added that it could be related to the immune response generated by the shots.
Dr. Ofer Levy, the director of the Precision Vaccines Program at Boston Children’s Hospital, agreed.
He noted that Pfizer’s and Moderna’s vaccines have been linked to a small risk of myocarditis. That condition, he said, may also be related to the immune response generated by the shots. Still, the myocarditis risk is significantly higher after a Covid infection than after vaccination.
Researchers should further explore the immune response to shots, because “the better we understand how the adverse events work, the smarter we can become in designing better vaccines in the future,” Levy said.
Other vaccines have also been linked to POTS in early accounts, but further research did not establish a causal link.
The HPV vaccine Gardasil, for example, was thought to cause POTS based on early reports, but subsequent reviews found that not to be the case, said Dr. William Schaffner, an infectious diseases expert at Vanderbilt University Medical Center, who was not involved with the new research.
The link between an infection — including Covid — and POTS, however, is more well-established.
"Many conditions can trigger POTS, including viral infections such as SARS-CoV-2, the virus that causes Covid-19," Dr. Bala Munipalli, a physician who heads the Post-Acute Sequelae of Covid Clinic at the Mayo Clinic in Jacksonville, Florida, said in an email.
POTS following other types of infection is not uncommon, Schaffner said. The condition has been linked to a number of viral or bacterial infections, including influenza, mononucleosis and Lyme disease.
Dr. Daniel Dudenkov, a physician at the Mayo Clinic, said that although Covid vaccines may be associated with POTS, it is important to keep in mind that Covid infection itself is much more likely to lead to POTS.
"Vaccines continue to be an important strategy to fight against Covid and its effects," he said.
Schaffner agreed, saying the event following vaccination is "rare."
"The risk of this happening is much greater with Covid than it is with the vaccine. So please get vaccinated," he said.