Experts have previously linked COVID-19 infection and long COVID-19 to a debilitating condition called POTS, which causes symptoms like dizziness, palpitations and elevated heart rate when standing up.

Less clear: Was there an association between POTS and COVID-19 vaccines?

A new study in the journal Nature Cardiovascular Research offers some clues.

POTS, or postural orthostatic tachycardia syndrome, affects the autonomic nervous system, which controls involuntary functions like breathing and heartbeat.

A two-year study of nearly 300,000 patients from the Cedars-Sinai Health System in Los Angeles County found POTS-related diagnoses were indeed higher after COVID-19 vaccinations.

However, the odds of that rare side effect were five times higher among people who had been infected by COVID-19 — another point in the pro-vaccination column.

As an observational study, the paper requires more research to confirm its conclusions. But its observations about post-COVID-19 POTS rates do match previous studies.

Myocarditis, a virus-linked inflammation of the heart wall, was still the most common post-COVID-19 condition diagnosed, followed by other autonomic nervous system problems collectively known as dysautonomia; POTS; mast cell activation syndrome, which causes repeated episodes of severe allergic reactions; and urinary tract infection.