Left atrium: the last bulwark before overt heart failure.

Heart failure (HF) with preserved ejection fraction (HFpEF) has emerged as an important public health issue in recent years. It represents the most common type of HF in ambulatory setting, and it has been recognized as a different entity from the reduced ejection fraction (EF) form. In HFpEF, continuous growing attention has been focused on the role of the left atrium (LA) in preserving good ventricular function and asymptomatic condition of the patient since the very first stages of diastolic dysfunction (DD). Non-invasive and complete echocardiographic evaluation of diastolic phase cannot exempt from accurately analyzed LA size, mostly LA volume, and its function, in particular LA myocardial deformation by speckle tracking echocardiography (STE). This review examines the expanding role of the LA in DD and HFpEF and the importance of its complete assessment in various settings, from diagnosis to correlation with major cardiovascular events.