ABSTRACT
Introduction: Studies have reported that patients with SARS-CoV-2 virus infection present with arterial hypoxemia, although without symptoms of this alteration, that is, they do not present a sensation of dyspnea, together with adequate pulmonary distensibility, which has been called silent hypoxemia. A possible damage at the level of the autonomic nervous system in the pathways that regulate the perception of hypoxia and the generation of dyspnea is proposed. Our objective is to study heart rate variability and sympathetic skin response in mild and moderate post-SARS-CoV-2 infection patients at the Luis Guillermo Ibarra Ibarra National Rehabilitation Institute who have presented oxygen saturation less than 90% at some point during or after infection. Method(s): 30 patients 14 females, mean age of 52.9 years (27-59) were included in the study. Lower limb nerve conduction studies, as well as autonomic testing were performed: heart rate variability during rest, deep breathing with E:I difference, postural standing 30:15 test, and sympathetic skin response were performed in all patients. A questionnaire about symptoms of cough, dyspnea dysgeusia, headache, myalgia, anosmia, fever, and fatigue were applied. All patients reported SpO2 below 90% at some point between symptoms and autonomic tests performed. Result(s): Nerve conduction studies were normal on all patients. Sympathetic skin response was also normal in all patients. Heart rate variability in rest was abnormal in one patient, and heart rate variability during deep breathing was abnormal in four patients. There was no significant association between these abnormalities and symptoms reported. Another finding was a tendency to postural tachycardia during the 30/15 test in 7 patients. Conclusion(s): Autonomic tests are not commonly abnormal in mild and moderate Sars-cov-2 patients, of the tests applied deep breathing was abnormal in 12% of patients, and a tendency to postural tachycardia was also observed. Bibliography -Baron R, et al. Heart rate variability. Recommendations for the practice of clinical neurophysiology: guidelines of the International Federation of Clinical Physiology. 1999. -Eshak N, et al. Dysautonomia: An Overlooked Neurological Manifestation in a Critically ill COVID[1]19 Patient. Am J Med Sci. 2020 Jul 17;S0002-9629(20)30316-5. -Goldstein D. The extended autonomic system, dyshomeostasis, and COVID-19. Clin Auton Res. 2020 Aug;30(4):299-315. Copyright © 2022