Prognostic Value of Delta LUS Score of Patients Hospitalized for Acute Heart Failure

Inclusion Criteria: * Patients aged over 18 years, * Patients hospitalized in the emergency department for dyspnea having as etiology an acute heart failure and in whom will be performed two pulmonary ultrasound examinations (at entry and exit). Exclusion Criteria: * Age less than 18 years * Dyspnea of non-cardiac etiology (cause: pulmonary, traumatic, toxic...) * Altered state of consciousness (Glasgow score\<14) * Hemodynamic instability: presence of peripheral signs of shock, use of vasoactive drugs * Mechanical ventilation from the outset * Cardiorespiratory arrest * Inability to give consent to the study * Missing one of two ultrasound examinations * Unable to make telephone contact after one month.