Autonomic function testing in long-COVID syndrome patients with orthostatic intolerance.

The association between dysautonomia and long-COVID syndrome has gained considerable interest. This study retrospectively characterized the findings of autonomic reflex screen (ARS) in long-COVID patients presenting with orthostatic intolerance (OI). Fourteen patients were identified. All patients had normal cardiovagal function and 2 patients had abnormal sudomotor function. The head-up tilt table (HUTT) was significantly abnormal in 3 patients showing postural orthostatic tachycardia syndrome (POTS). CASS ranged from 0 to 2. The most common clinical scenario was symptoms of orthostatic intolerance without demonstrable HUTT orthostatic tachycardia or orthostatic hypotension (OH) (n = 8, 57 %). In our case series, most long-COVID patients presenting to our laboratory with OI had no significant HUTT abnormalities; only 3 patients met the criteria for POTS.