Canadian Journal of Cardiology



      The novel coronavirus has negatively impacted the health and economy of Canada and the world. While most patients recover, many patients are left with residual symptoms even several months after resolution of the acute illness (“Post-Acute Sequalae of COVID-19” [PASC]; or “Long COVID). Symptoms can include fatigue, light-headedness, and achycardia/palpitations, which are common in cardiovascular autonomic disorders such as Postural Orthostatic Tachycardia Syndrome (POTS), Initial Orthostatic Hypotension (IOH), Orthostatic Hypotension (OH), and Inappropriate Sinus Tachycardia (IST). Currently, we do not know the prevalence of objective autonomic abnormalities in patients with PASC, nor if there are sex differences. We aimed to determine the prevalence of objective autonomic abnormalities, and whether there was a sex-difference, among patients with PASC.

      Methods and Results

      Patients with PASC (n=61; F=49; Age=45±11 years) underwent autonomic function testing with beat-to-beat hemodynamics for 10 min supine followed by a 10 min active stand 397±131 days after their COVID infection. Patients were evaluated for hemodynamic criterion for POTS (ΔHR≥30 bpm within 10 min), IOH (transient ΔSBP≥40mmHg within 45s), OH (ΔSBP≥20mmHg within 3 min), and IST (supine HR>100 bpm). Categorical data were analyzed with a Fisher’s Exact test. The POTS criterion was met in 18 (30%) patients with PASC, while the IOH criterion was met in 40 (66%) patients. The IST and OH criteria were each seen in 1 patient. Overall, 44 (72%) patients met the criterion for at least 1 of these disorders. When analyzed by sex, the POTS criterion was met in 18 (37%) females, but no males (P=0.01). IOH criterion was met in females (69%) and males (50%; P=0.2) at a similar frequency. The single OH and IST patients were female. Overall, there was a non-significant trend for more females (78%) than males (50%; P=0.06) meeting the criterion for at least 1 of these disorders.


      Many patients with PASC have objective evidence of autonomic cardiovascular abnormalities. The most common abnormality is IOH, followed by POTS. IOH will be missed unless an active standing protocol is used. POTS was much more common in females than males, but IOH was evenly split between sexes. Overall, there is a trend toward increased frequency of autonomic cardiovascular disorders in females than males. On behalf of the Canadian Long Covid Autonomic Network (CaLoCAN).