ABSTRACT
PURPOSE: cardiovascular response to stress (such as hypoxemia) is mediated by the autonomic nervous system (ANS) and heart rate variability is an important part of it. Neurotropism is an important feature of SARS-CoV-2 infection and clinical dissociation between hypoxemia and the cardiovascular response has been reported. We proposed that HRV could be used to identify, at admission in the intensive care unit (ICU), those patients who were going to need invasive mechanical ventilation (IMV) during their stay. METHODS: We performed a prospective single-centre observational study analyzing adult patients admitted to ICU at Hospital Clínico San Carlos with respiratory failure due SARS-CoV-2 pneumonia but not under IMV. We recorded continuous EKG waveforms and obtained time and frequency domains and non-linear dynamics HRV metrics. RESULTS: 47 patients were screened and 27 were finally analyzed. 15 (55.5%) of them required intubation and IMV. Heart rate was 80 beats/min in each group. HRV metrics were similar between groups in the time domain, frequency domain and after using nonlinear analysis. However, when comparing against literature control, Covid-19 patients admitted in the ICU had a diminished HRV but higher heart rates. CONCLUSION: We found that HRV on ICU admission didn't discriminate patients requiring IMV. We found that Covid-19 patients had a diminished HRV although having higher heart rates than healthy literature controls.