Background Acute dyspnea (AD) is one of the main reasons for admission to the Emergency Department (ED). In the last years integrated ultrasound examination (IUE) of lung, heart and inferior vena cava be-come an extension of clinical examination for a fast differential diagnosis. The aim of present study is to assess the feasibility and diagnostic accuracy of diastolic function evaluation for diagnosing acute heart failure (aHF) in patients with acute dyspnea. Methods We included 113 patients presenting to the ED of CTO Hospital in Naples (Italy) for AD. All pa-tients underwent IUE of lung-heart-IVC with a portable ultrasound device. Left ventricle diastolic function was assessed using pulse wave doppler at the tips of the mitral valve and E wave velocity and E/A ratio were recorded. The FINAL diagnosis determined by two expert reviewers: acute HF or non-acute HF (non-aHF). We used 2 × 2 contingency tables to analyze sensitivity, specificity, positive predictive and negative predictive value of ultrasound parameters for the diagnosis of AD, comparing with the FINAL diagnosis. Results Lung ultrasound (LUS) showed high sensitivity, good specificity and accuracy in identification of patients with HF. However the highest accuracy was obtained by diastolic function parameters. The E/A ratio, detected in patients in sinus rhythm, showed the highest diagnostic performance with an AUC for aHF of 0.913. Conclusion In patients presenting with AD E/A ratio is easy to obtain in a fast ultrasound protocol and showed an excellent accuracy for diagnosis of acute HF.