Eligibility
We conducted the study during Iran’s third COVID-19 wave in November 2020. The study population included RCMRC’s health care workers infected with COVID-19. An overall 319 employees in this period were advised to be quarantined due to suspicious symptoms by infectious disease specialists. We enrolled 137 individuals with a definite COVID-19 infection confirmed by a positive RT-PCR test. Of these, 33 patients refused to undergo echocardiography, and four were excluded from the study due to preexisting cardiovascular disease (3 had a history of cardiac surgery, and 1 had moderate valvular aortic stenosis). Therefore, in the early echocardiography, 100 patients underwent comprehensive echocardiographic examination 6 to 8 weeks after recovery and returning to work. Of those who were performed early echocardiography, 63 patients agreed to undergo the late echocardiography six months after the COVID-19 diagnosis. They were otherwise healthy with no underlying disease (e.g., structural heart disease, chronic obstructive pulmonary disease, and chronic kidney disease).