Discrimination between cardiac and non-cardiac causes of dyspnea can be challenging, causing excessive delay before adequate therapy. In clinical practice lung ultrasound (LUS) is becoming an easy and reliable noninvasive tool for the evaluation of dyspnea and can shorten the time to diagnosis .However the reproductibility of this test was not extensively studied.

Dyspnea is one of the most distressing situations for the patient . Emergency cases do not always present in conditions that are ideal for immediate diagnosis, which sometimes compromises outcome. Physical examination, laboratory findings and radiography are imperfect, resulting in a need for sophisticated test results that delay management.

Lung ultrasonography is becoming a standard tool in critical cases in the ED.

the investigators aim to perform ultrasonography on consecutive patients admitted to the ICU with dyspnea, comparing lung ultrasonography results on initial presentation with the final diagnosis by the ICU team.

Three items were assessed: artifacts (horizontal A lines or vertical B lines indicating interstitial syndrome), lung sliding, and alveolar consolidation and/or pleural effusion, these items were grouped to assess ultrasound profiles.

This study assesses the potential of lung ultrasonography to diagnose heart failure.The second aim of this study was to evaluate the inter-observer reproducibility of LUS performed by ED residents in the evaluation of cardiac causes of acute dyspnea.

Patients presenting to the ED with acute dyspnea will be prospectively enrolled in this study. In each patient, LUS was performed by two ED residents blinded to clinical diagnoses.

AHF was determined on the base of clinical exam, chest x-ray , brain natriuretic peptide (BNP) and echocardiographic findings.

A patient lung comet score (LCS) was obtained by summing the number of comets in each of the scanned spaces.

Then the probability of AHF was defined as :

low probability (LCS<15) intermediate probability (15 <LCS<30), and high probability (LCS>30 ).

Inclusion Criteria:

• non traumatic dyspnea with the final diagnosis of heart failure

Exclusion Criteria:

• impossibility to give consent to participate in the study
• post traumatic dyspnea
• pregnant women
• need for endotracheal intubation or inotropic drugs
• patients who were deemed too unstable for sonography by the treating team

all patients admitted to the ED with acute dyspnea, with the final diagnosis of heart failure