Inclusion Criteria:  Subject should be between the ages of 18 and 40 with DOE (dyspnea on exertion) for 3 - 12 months Subjects recovered from acute, polymerase chain reaction (PCR) positive, COVID-19 infection Recovery from COVID-19 will be defined as substantial improvement in or essential resolution of initial clinical symptoms Demonstration of tachycardia and/or dyspnea with minimal activity (subjectively different than pre-COVID 19 infection state) Abnormal HUTT (heads up tilt test) Normal chest x-ray Left ventricular ejection fraction (LVEF) >50% by transthoracic echocardiography Zva >3.5 as calculated from TTE (transthoracic echocardiogram). Hemoglobin/Hematocrit within normal laboratory standards Thyroid-stimulating hormone (TSH) within normal laboratory standards  Exclusion Criteria:  Active pregnancy (negative pregnancy test is the standard of care prior to HUTT)  Demonstrate a primary cause of appropriate DOE and sinus tachycardia  Fevers/infection Hypovolemia Anemia Hyperthyroidism Alcohol/drug/medication withdrawal Currently taking beta blocker medications Currently being treated for pre-existing neurally mediated hypotension/syncope or known dysautonomia. Medical history of chronic lung disease or reactive airway syndrome.