ABSTRACT
The uncontrolled hyper-inflammation in critically ill patients with COVID-19 might be associated with a dysfunction of the cardiovascular regulatory mechanisms. In order to estimate the involvement of cardiovascular control in limiting the risk of mortality in COVID-19 patients we assessed the degree of asynchrony between heart period (HP) and systolic arterial pressure (SAP) variability at rest in supine condition (REST) and during an orthostatic challenge, namely the modified head-up tilt (MHUT), in 18 COVID-19 patients (age: 62± 10 yrs, 15 men) admitted in intensive care unit (ICU) for pneumonia. The patients were distinguished in two groups, i.e. survivors (SURVs) or non survivors (noSURVs) according to the outcome. Asynchrony between HP and SAP was assessed via a model-free nonlinear marker in the information domain, i.e. cross-sample entropy (CSampEn). Neither demographic indexes nor time domain markers could separate the two groups and this result held regardless of the experimental condition. Conversely, CSampEn could and, more precisely, noSURVs subjects had a significantly larger HP-SAP asynchrony when compared to SURVs in response to MHUT. We conclude that measures of the derangement of the cardiovascular control might be helpful to stratify the risk of mortality in COVID-19 critically ill patients. © 2022 Creative Commons.