Enhanced External Counterpulsation to Treat Long COVID-19 Fatigue

Participants of this trial will be patients recovering from acute COVID-19, 3-12 months following the acute infection, and suffering from fatigue with a Patient-Reported Outcomes Measurement System (PROMIS)-Fatigue short-form (SF)-7a score of \> 50. Exclusion criteria will include contra-indications for EECP (see protocl). Intervention, comparisn and outcomes are described above. Study plan: participants will be invited using social media, after filling a fatigue score (PROMIS) to test for eligibility. Those with a score of \> 50 will be invited for a study visit. Study visit 1 will include informed consent, followed by physician interview, physical examination, ECG; and will be referred for completion of blood tests including complete blood count (CBC) to rule out significant anemia (Hb\< 12 for men or hb \<10 for women) and serum beta human chorionic gonadotrophin (bHCG). Eligible patients will then be randomized into two groups for treatment with EECP vs sham procedure. In study Visit 2 they will answer several questionnaires, perforn EndoPAT test to assess endothelial dysfunction, and six-minute walk test, followed by either: 1. Treatment group- 1 hour EECP session 2. Sham group - 1 hour of a sham EECP session (patients will be hooked to the EECP device but it will be set to the lowest setting, and lowest frequency, therefore unable to create a sufficient rise in diastolic return). This visit will be followed by 3 times weekly 1 hour sessions for 5 weeks (15 sessions) of either EECP or sham procdeure, according to randomization group. Questionnaire that will be used before and after the intervention will include: 1. Fatigue evaluation using the PROMIS 7a form, attached in appendix (as validated on Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)patients) 2. Functional capacity evaluation using the Duke Activity Status Assessment (DASI) (https://www.mdcalc.com/duke-activity-status-index-dasi); 3. Shortness of Breath using the modified Medical Research Council dyspnea scale 4. Quality of life using the SF-36 questionnaire. 6mwt and endothelial dysfunction by EndoPAT will be held following the last treatment. Study Visit 3 (3 months following starting treatment) will be a final Interview to assess improvement by questionnaires, as well as time to return to activity and time to return to work.