Functional Capacity in Patients Post Mild COVID-19

Patients recovered from mild coronavirus 2019 (COVID-19) disease without pulmonary involvement may experience long-term physical impairment and dyspnea. The investigators aim to characterize physiologic limitations in patients who recovered from mild COVID-19. Methods: Pulmonary function tests (PFTs), 6-minute walk test (6MWT), echocardiography and cardiopulmonary exercise test (CPET) will be completed in patients recovered from mild COVID-19 disease with prolonged dyspnea (Subgroup "A") and compared to patients recovered from moderate/severe COVID-19 (subgroup "B") and to non-COVID-19 patients with unexplained dyspnea (subgroup "C").