Abnormal Right Ventricular Free Wall Strain Prior to Prone Ventilation May Be Associated With Worse Outcome of Patients With COVID-19-Associated Acute Respiratory Distress Syndrome

We investigated the effect of prone ventilation on right ventricular (RV) function of intubated patients with COVID-19-associated acute respiratory distress syndrome by measuring both conventional RV functional variables (namely, tricuspid annular peak systolic velocity, tricuspid annular plane systolic excursion, and fractional area change) and right ventricular free wall strain (RVFWS) using transthoracic speckle-tracking echocardiography at baseline (before prone positioning), 18 hours after prone positioning, and 1 hour after supine repositioning. We found that transthoracic echocardiography was feasible in a considerable proportion (nine patients, 75% of our cohort) of patients undergoing prone ventilation. Also, abnormal as opposed to normal RVFWS values (in the absence of conventional variables of RV dysfunction) at baseline were associated with higher mortality (100% vs 20%; p = 0.048). Finally, we found that, among patients without acute cor pulmonale or conventional markers of RV dysfunction, one session of prone ventilation may not affect right myocardial strain.