For patients with post-acute sequelae of SARS-CoV-2 infection (PASC), circulatory impairment, abnormal ventilatory patterns, and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are common, according to a study published in JACC: Heart Failure. Noting that about 20% of patients who recover from COVID-19 remain symptomatic, researchers performed cardiopulmonary exercise testing and symptom assessment for ME/CFS in 41 patients with PASC after COVID-19. Among participants, 58.5% had a peak oxygen consumption (VO2) of less than 80% of predicted, all of whom had a circulatory limitation to exercise. Among 17 patients with normal peak VO2, 15 had ventilatory abnormalities, including a peak respiratory rate of greater than 55 or dysfunctional breathing. In the whole cohort, 88% had ventilatory abnormalities with dysfunctional breathing, increased slope of minute ventilation to carbon dioxide production, and/or hypocapnia end tidal pressure of carbon dioxide. The criteria for ME/CFS were met by 19 patients.