We hypothesize that recovered COVID-19 patients suffer long term cardiovascular and pulmonary complications, which can be detected by point of care ultrasound. The goal is to comprehensively delineate the long term cardiovascular and pulmonary ultrasound findings in recovered COVID-19 patients, identify risks factors for prolonged heart/lung injury, evaluate long term effects of applied treatment, and assess late medication/vaccine side effects in COVID-19 patients.

Aim 1: To examine the long term cardiac involvements of recovered COVID-19 patients at 3, 6, 12 months after being discharged from the hospital or symptom resolution with electrocardiogram (ECG) and echocardiography. 12 lead ECG will be obtained for all patients. Transthoracic echocardiography will be performed using GE Vivid E9 ultrasound system to measure left ventricular (LV) dimensions, LV volumes and LV ejection fraction (EF), wall thickness, LV mass, and LV remodeling index. LV diastolic function will be characterized by maximum velocities of mitral inflow E and A waves, E/A ratio, E/E' ratio (maximum myocardial velocities (E') of the lateral mitral annulus), isovolumetric relaxation time, tricuspid regurgitation velocity, and left atrial volumes. Right-ventricular function will be assessed by tricuspid annular plane systolic excursion (TAPSE), pulmonary acceleration time, and by estimation of systolic pulmonary artery pressure. We will evaluate mitral, aortic, tricuspid and pulmonic valvular stenosis and regurgitation. In addition, speckle tracking echocardiography will be used to detect subclinical impairment of myocardium in patients who have grossly normal LVEF. Lastly, inferior vena cava will be measured to assess patients' volume status.

Aim 2: To evaluate long term pulmonary involvements of recovered COVID-19 patients at 3, 6, 12 months after being discharged from the hospital or symptom resolution with pulse oximetry, bedside spirometry and lung ultrasound. Pulse oximetry, bedside spirometry, and lung ultrasonography (LUS) will be performed for all patients. The pathological LUS features for every zone will be reported as: (1) normal appearance (A lines, < 3 B lines), (2) pathologic B lines (≥3 B lines), (3) confluent B lines, (4) thickening of the pleura with pleural line irregularities (subpleural consolidation < 1 cm), (5) consolidation (≥ 1 cm), (6) pleural effusion. The LUS score, used as a correlate of loss of lung tissue aeration, as well as a normalized LUS score corrected for the number of examined zone, will be calculated in every patient.

Aim 3: To diagnose long term vascular involvements of recovered COVID-19 patients at 3, 6, 12 months after being discharged from the hospital or symptom resolution with vascular ultrasound. A trained physician or sonographer will use high resolution gray-scale imaging, color Doppler ultrasound and spectral analysis with pulse wave Doppler to examine bilateral upper/lower extremity venous and arterial systems and carotid arteries for thrombosis, atheroma, and stenosis.

Inclusion Criteria:

• >18 years of age
• Consent to participate in this research
• Confirmed SARS-CoV-2 infection by RT-PCR or serological tests.

Exclusion Criteria:

• Refusal to participate in this research

Asymptomatic/Mild Group: 50 confirmed COVID-19 patients who showed no or only mild respiratory/GI symptoms; Moderate Group: 50 confirmed COVID-19 patients who were able to maintain oxygen saturation above 92% (or above 90% for patients with chronic lung disease) with up to 4 L/min oxygen via nasal prongs; Severe Group: 50 confirmed COVID-19 patients who had oxygen saturation less than 92% at rest and PaO2/FiO2 between 200 and 300; Critical Group: 50 confirmed COVID-19 patients who had PaO2/FiO2 less than 200 or required mechanical ventilation. Control Group: 50 age and sex-matched controls.