Left atrial strain in left ventricular diastolic dysfunction: have we finally found the missing piece of the puzzle?

The noninvasive estimation of diastolic function with echocardiography as a surrogate of left ventricular filling pressure is considered an essential step in the clinical evaluation of patients with conditions predisposing to heart failure (HF). Latest algorithms for the assessment of diastolic dysfunction (DD) lay on several 2D standard parameters and describe a precise grading to quantify its severity. The persistence of a "gray zone" of values in which DD quantification is not possible, together with an epidemiological increase of conditions predisposing to heart failure with preserved ejection fraction (HFpEF), has led to the search and use of parameters with higher specificity and sensitivity: one of these is left atrial (LA) longitudinal strain in the frame of speckle tracking echocardiography (STE). LA anatomy and mechanics are crucial for preserving left ventricular (LV) function and asymptomatic condition of the patient. LA longitudinal strain is angle-independent, thus overcoming Doppler limitations, and provides reproducible measures of LA deformation. This review examines the latest evidences concerning the use of LA longitudinal strain in the assessment of diastolic function and HFpEF, with a particular focus on its role in standard echocardiographic algorithms or as a lone parameter to guide diagnosis and therapeutic management.