LOS ANGELES (KABC) -- With billions of shots given worldwide, COVID-19 vaccines have proven to be safe and effective.
Earlier research found a connection between COVID vaccines and mild heart inflammation, especially in adolescent and young adult males.
Now, Cedars Sinai scientists are learning more about the vaccine's connection to a little-known heart condition.
POTS - postural orthostatic tachycardia syndrome - can cause rapid heartbeat, dizziness and other nervous system and heart issues.
Kim Ryberg, now 34, started experiencing POTS shortly after she contracted the Epstein Barr virus at age 12. Since then, she's had severe episodes of dizziness and fainting.
"Every time I'd stand up, I would see a black tunnel at the edge of my vision."
In her late 20s, she says, there were times it got so bad she couldn't even walk up a single flight of stairs.
Her doctors say exposure to Epstein Barr caused dysfunction to her autonomic nervous system which controls heart rate and blood pressure.
Dr. Alan C. Kwan treats POTS patients at a specialized clinic at Cedars Sinai. He says most patients take at least two years and see multiple doctors before they are properly diagnosed.
When he started hearing about people experiencing POTS after getting the COVID vaccine, he and his team did a deep dive into patient health records.
"There does appear to be a small signal associating COVID-19 vaccines with POTS occurring after the vaccine exposure within 90 days," Kwan said.
The study data suggest the risk of developing POTS after vaccination is less than 5 cases per million doses.
You are actually more likely to develop POTS if you are infected with the coronavirus, more than the chances after vaccination, Kwan's research found.
"The risk of contracting POTS from the infection was significantly higher, more than five times higher than from vaccination," Kwan said.
Kwan says not only does the COVID vaccine confer protection against disease, but the study also finds it offers substantial protection against POTS as well.
Kwan says people should still get vaccinated.
"The probability says this will help protect you and those around you."
He hopes his research will help connect people with POTS to proper specialty care.
While Ryberg did experience some symptoms after vaccination, she's confident the COVID vaccine saved her from something much worse.
"I believe that's what protected me and kept me out of the hospital even though I was sick," she said. "It's not nearly as sick as I have been in the past and could have been."