I know this is an old post but I wanted to share.
I had always felt dizzy when I stood up and my vision would darken but I would not ever pass out, this started in my teens. In 2020 I got COVID before I had any vaccines. I was fine until I wasn't. I had no symptoms at all for the first 4 days. Then I felt my heart racing and heart palpitations, which I had had palpitations before, but not the heart racing sensation. I communicated this to my NP and she said to monitor my HR. If I stood up and walked, just 5-6 steps, it would go from 80s (resting) all the way up to 130s-160s almost immediately. I could not go up the stairs without feeling faint so I was not allowed to go upstairs at all. Other than that, no symptoms. No cough, no sinus anything, no fever, no GI issues, nothing at all. At about the 2 week mark, I woke up one day feeling my chest tight. NP said to go to the ER just in case, I was diagnosed with pneumonia. HR kept being an issue and the palpitations. I was not allowed back to work since I couldn't stand for very long and my HR remained high for as long as I was standing. I went to see a cardiologist, she diagnosed me with POTS and told me that they had seen an increase in diagnoses of patients post-COVID. She said that in my case, it sounded like I already had POTS but a very mild form and COVID exacerbated my symptoms to where they became a problem. I wore a cardiac monitor for a week and we realized I had an arrythmia, the palpitations I was so used to feeling and my sudden bursts of anxiety were all the arrythmia, PACs. I started taking salt pills twice a day, electrolytes and compression socks, as well as flecainide for the arrythmia. I saw her again 6 months later and I had significantly improved so she said I could stop the salt pills and monitor symptoms. I stopped the compression socks because I hated them and noticed I was still doing fine. I kept the electrolytes for another year and since then I take them every so often, especially if I am having a flare or I can feel that it's gonna be a day. But since COVID my POTS is definitely worse than it was.
Two months ago, I got COVID for the second time. I was worried about having a POTS flare, but to my surprise I didn't. I again had no symptoms except for being tired. My HR did increase a bit when standing but nothing like the first time around. So round two of covid seems like I won this time around.