Left atrium as key player and essential biomarker in heart failure.

This article reviews roles of the left atrium as regulator of left ventricular filling, as compensatory reserve in left ventricular dysfunction and as diagnostic marker in patients with cardiovascular disorders. Application of novel imaging tools to assess left atrial function and their integration with conventional clinical methods are discussed. This includes a review of clinical applications of left atrial strain as a method to quantify the reservoir and booster pump components of left atrial function. Emerging methods for assessing left atrial wall stiffness and active work by pressure-strain loop analysis are discussed. Recommendations for how to apply left atrial strain in clinical routine to diagnose elevated left ventricular filling pressure are provided. Furthermore, a role for left atrial strain in the diagnostic work-up in patients suspected of pre-capillary pulmonary hypertension is proposed. The article also reviews how to implement parameters of atrial structure and function in clinical routine as recommended by recent international guidelines for imaging of heart failure.