Left atrial function index: did we end up waiting for Godot?

Abstract

> ‘ Estragon : What do we do now? Vladimir : Wait for Godot.’1 In the last decades, several authors focused their efforts on the evaluation of atrial function. It is now well known that atria play a key role in the physiological equilibrium of the heart. Indeed, atria are not mere conduits that allow blood to pass from the big vessels to the ventricles. In each cardiac cycle, atria, and particularly the left atrium (LA), act as reservoirs, receiving pulmonary venous return during left ventricular (LV) systole; as a conduit, transferring blood to the LV during early diastole; and as a pump, actively pushing blood to the LV in late diastole, providing in each of these phases 40%, 35%, and 25% of atrial contribution to stroke volume, respectively2 ( Figure 1 ). Interestingly, LA contributions became more important in the first stages of heart failure and its changes allow the LV to keep a precarious equilibrium until the increased LV filling pressure overcomes it, leading to the onset of symptoms. Consequently, LA function became a relevant predictor of prognosis in several clinical settings, including heart failure with preserved ejection fraction (HFpEF),3 coronary artery disease,4 and heart valve diseases,5 etc. Several echocardiographic parameters have been developed to evaluate atrial function, such as the peak A wave velocity of transmitral flow in late diastole obtained by pulsed wave Doppler and its velocity time integral (VTI), the A’ velocity using Doppler tissue imaging, LA …