Anterior vs lateral symmetric interstitial syndrome in the diagnosis of acute heart failure.

Acute dyspnea due to acute heart failure (AHF) is one of the most common reasons for admission to the Emergency Department (ED). The importance of lung ultrasound (LUS) examination in the diagnostic workup of AHF has been widely established. Limited anterior LUS examination for the diagnosis of AHF is controversial. This study compares the accuracy of LUS examination limited to the anterior or lateral lung zones for the diagnosis of AHF and their accuracy among patients with different levels of hypoxemia according to PO2/FiO2 ratio evaluation. We analyzed 170 patients admitted to the ED for acute dyspnea, who underwent multi-organ ultrasound examination of lung, heart and inferior vena cava for differential diagnosis. The thorax was examined following a simplified protocol that provides two scans at each side (anterior and lateral) to sample upper and lower lobes and the presence or the absence of interstitial syndrome (IS) was evaluated. The presence of anterior symmetric IS exhibited lower accuracy than lateral symmetric IS in the diagnosis of AHF in the whole population, but its diagnostic accuracy improves in sub-groups of patients with severe and critical hypoxemia.