Speckled Tracking of Pleura-A Novel Tool for Lung Ultrasound; Distinguishing COVID-19 from Acute Heart Failure

For the acutely dyspneic patient, discerning bedside between acute decompensated heart failure (ADHF) and COVID-19 is crucial. A lung ultrasound (LUS) is sensitive for detecting these conditions, but not in distinguishing between them; both have bilateral B-lines. The Blue protocol uses pleural sliding to differentiate decreased pneumonia; however, this is not the case in ADHF. Nonetheless, this pleural sliding has never been quantified. Speckled tracking is a technology utilized in the echocardiography field that quantifies the motion of tissues by examining the movement of ultrasound speckles. We conducted a retrospective study of LUS performed in emergency room patients during the COVID-19 pandemic. Speckled tracking of the pleura by applying software to the B-mode of pleura was compared between COVID-19 patients, ADHF patients, and patients with no respiratory complaints. A significant difference was found between the patient groups on speckled tracking both in respect of displacement and velocity. ADHF had the highest displacement, followed by COVID-19, and then non-respiratory patients: 1.63 +/- 1.89, 0.59 +/- 0.71, and 0.24 +/- 0.45, respectively (p < 0.01). A similar trend was seen in velocity with ADHF having the highest velocity 0.34 +/- 0.37, followed by COVID-19 0.14 +/- 0.71, and non-respiratory patients 0.02 +/- 0.09 (p <0.01). Speckled tracking of the pleura is a potential tool for discerning between different causes of dyspnea.