Evidence for impaired chronotropic responses to and recovery from 6‐minute walk test in women with post‐acute COVID‐19 syndrome

NEW FINDINGS: What is the central question of this study? Are chronotropic responses to a 6‐minute walk test different in women with post‐acute coronavirus disease 2019 (COVID‐19) syndrome compared with control subjects? What is the main finding and its importance? Compared with control subjects, the increase in heart rate was attenuated and recovery delayed after a 6‐minute walk test in participants after infection with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). Women reporting specific symptoms at time of testing had greater impairments compared with control subjects and SARS‐CoV‐2 participants not actively experiencing these symptoms. Such alterations have potential to constrain not only exercise tolerance but also participation in free‐living physical activity in women during post‐acute recovery from COVID‐19. ABSTRACT: The short‐term cardiopulmonary manifestations of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) are well defined. However, the implications of cardiopulmonary sequelae, persisting beyond acute illness, on physical function are largely unknown. Herein, we characterized heart rate responses to and recovery from a 6‐minute walk test (6MWT) in women ∼3 months after mild‐to‐moderate SARS‐CoV‐2 infection compared with non‐infected control subjects. Forty‐five women (n = 29 SARS‐CoV‐2; n = 16 controls; age = 56 ± 11 years; body mass index = 25.8 ± 6.0 kg/m(2)) completed pulmonary function testing and a 6MWT. The SARS‐CoV‐2 participants demonstrated reduced total lung capacity (84 ± 8 vs. 93 ± 13%; P = 0.006), vital capacity (87 ± 10 vs. 93 ± 10%; P = 0.040), functional residual capacity (75 ± 16 vs. 88 ± 16%; P = 0.006) and residual volume (76 ± 18 vs. 93 ± 22%; P = 0.001) compared with control subjects. No between‐group differences were observed in 6MWT distance (P = 0.194); however, the increase in heart rate with exertion was attenuated among SARS‐CoV‐2 participants compared with control subjects (+52 ± 20 vs. +65 ± 18 beats/min; P = 0.029). The decrease in heart rate was also delayed for minutes 1–5 of recovery among SARS‐CoV‐2 participants (all P < 0.05). Women reporting specific symptoms at the time of testing had greater impairments compared with control subjects and SARS‐CoV‐2 participants not actively experiencing these symptoms. Our findings provide evidence for marked differences in chronotropic responses to and recovery from a 6MWT in women several months after acute SARS‐CoV‐2 infection.