Functional Capacity in Patients Who Recovered From Mild COVID-19 With Exertional Dyspnea.

Infection with severe acute respiratory syndrome coronavirus-2 leads to severe disease requiring hospitalization in 20% of the cases. Respiratory failure from severe acute respiratory syndrome coronavirus-2 infection can range from mild pneumonia and hypoxia to life threatening hypoxia secondary to severe acute respiratory distress syndrome requiring intensive care unit and mechanical ventilation in about 12-24% of the hospitalized patients. Most patients are discharged with minimal or no long-term oxygen therapy while others are discharged with ongoing respiratory symptoms and long-term oxygen therapy. In the longer term, there is a significant concern that severe coronavirus disease 2019 can lead to organizing pneumonia and severe acute lung injury with evolution to widespread fibrotic changes as seen in fatal cases of coronavirus disease showing pulmonary fibrosis at autopsy. Studies in severe acute respiratory syndrome survivors, another corona virus infection, showed persistent and significant impairment of exercise capacity and health status over 24 months based on PFTs, 6-minute walk test and health questionnaire. Infection with respiratory syndrome coronavirus-2 has been also associated with multiple direct and indirect cardiovascular complications including acute myocardial injury, myocarditis, arrhythmias, and venous thromboembolism. However, long term cardiovascular consequences from coronavirus disease 2019 are still unknown. The investigators sought to determine the pulmonary, cardiac and other physiologic limitations in patients who recovered from severe coronavirus disease 2019 with physiologic tests including PFTs, echocardiography and cardio-pulmonary exercise test which is currently the most comprehensive physiologic test that can differentiate between the different limitations and add novel data regarding short and long term physiologic consequences of coronavirus disease 2019.