o date, the implications of cardiopulmonary sequelae -persisting beyond acute illness- on physical function are largely unknown.
The study team characterized heart rate (HR) responses to and recovery from a 6-minute walk test (6MWT) in women ≈3 months following mild-to-moderate SARS-CoV-2 infection compared to non-infected controls.
A total of forty-five women (n = 29 SARS-CoV-2; n = 16 controls; age = 56 ± 11 years; body mass index = 25.8 ± 6.0 kg/m2) completed pulmonary function testing and a 6MWT.
The study findings showed that SARS-CoV-2 participants demonstrated reduced total lung capacity (84 ± 8 vs. 93 ± 13%; P = .006), vital capacity (87 ± 10 vs. 93 ± 10%; P = .040), functional residual capacity (75 ± 16 vs. 88 ± 16%; P = .006), and residual volume (76 ± 18 vs. 93 ± 22%; P = .001) compared to controls.
No between-group differences were observed in 6MWT distance (P = .194); however, the increase in HR with exertion was attenuated among SARS-CoV-2 participants compared to controls (+52 ± 20 bpm vs. +65 ± 18 bpm; P = .029). The decrease in HR was also delayed for minutes 1–5 of recovery among SARS-CoV-2 participants (all P < 0.05).
Women reporting specific symptoms at time of testing had greater impairments compared with controls and SARS-CoV-2 participants not actively experiencing these symptoms.
The study findings provide evidence for marked differences in chronotropic responses to and recovery from a 6MWT in women several months following acute SARS-CoV-2 infection.
The study findings were published in the peer reviewed The Physiological Society’s journal Experimental Physiology. https://physoc.onlinelibrary.wiley.com/doi/10.1113/EP089965
Over 225 million individuals have contracted acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the coronavirus disease 2019 (COVID-19) pandemic. With progressive vaccination efforts, case incidence rates are declining; however, the functional consequences of cardiopulmonary sequelae persisting >3-4 weeks following the onset of initial symptoms, termed “post-acute COVID-19 syndrome” (Nalbandian et al., 2021), remain unclear.
Longitudinal monitoring of hospitalized SARS-CoV-2 patients has revealed restrictive defects and / or diffusion impairments in > 50% of patients in the months following discharge (Bellan et al., 2021; Orzes et al., 2021; Safont et al., 2021). Although male sex is recognized as a predictor for increased COVID-19 disease severity and mortality (Peckham et al., 2020), female sex has been associated with a greater risk for persistent diffusion impairments months into recovery (Bellan et al., 2021; Huang et al., 2021; Safont et al., 2021).
Additional data indicate that, following SARS-CoV-2 infection, women commonly report declining physical health or fatigue (Xiong et al., 2021) and are 3 to 4 times more likely to seek treatment for chronic symptoms (Davido, Seang, Tubiana, & de Truchis, 2020; Vanichkachorn et al., 2021). In particular, persistent cardiopulmonary abnormalities following a SARS-CoV-2 infection may reduce overall exercise tolerance in women.
The 6-minute walk test (6MWT) is a widely-used clinical assessment of functional exercise capacity (Lancaster, 2018); heart rate (HR) response to this test is a strong independent predictor of daily physical activity (Morita et al., 2018) and mortality (Holland et al., 2013; Swigris et al., 2009) in pulmonary disease patients.
However, it remains unclear whether chronotropic responses to a 6MWT are altered among women during post-acute recovery from COVID-19.