Cardiac Imaging for the Assessment of Left Atrial Mechanics Across Heart Failure Stages

Abstract

The left atrium (LA) is emerging as a key element in the pathophysiology of several cardiac diseases due to having an active role in contrasting heart failure (HF) progression. Its morphological and functional remodeling occurs progressively according to pressure or volume overload generated by the underlying disease, and its ability of adaptation contributes to avoid pulmonary circulation congestion and to postpone HF symptoms. Moreover, early signs of LA dysfunction can anticipate and predict the clinical course of HF diseases before the symptom onset which, particularly, also applies to patients with increased risk of HF with still normal cardiac structure (stage A HF). The study of LA mechanics (chamber morphology and function) is moving from a research interest to a clinical application thanks to a great clinical, prognostic, and pathophysiological significance. This process is promoted by the technological progress of cardiac imaging which increases the availability of easy-to-use tools for clinicians and HF specialists. Two-dimensional (2D) speckle tracking echocardiography and feature tracking cardiac magnetic resonance are becoming essential for daily practice. In this context, a deep understanding of LA mechanics, its prognostic significance, and the available approaches are essential to improve clinical practice. The present review will focus on LA mechanics, discussing atrial physiology and pathophysiology of main cardiac diseases across the HF stages with specific attention to the prognostic significance. Imaging techniques for LA mechanics assessment will be discussed with an overlook on the dynamic (under stress) evaluation of the chamber.

Molecular Changes in Prepubertal Left Ventricular Development Under Experimental Volume Overload

“…These results suggested that VO may result in conduction disorders, which may be associated with the increase of immune responses. These were consistent with recent observations in human beings, showing that conduction disorders were associated with atrial VO, which induces sudden death in patients with AR ( 31 , 32 ).…”

Prognostic Value of Left Atrial Strain in Heart Failure: A Systematic Review and Meta-Analysis

“…The use of PALS in place of left atrial volume index (LAVI) may contribute to a more accurate categorization of patients with indeterminate diastolic function (32). Moreover, PALS could provide prognostic significance independent of clinical and echocardiographic assessment, even in patients with HFpEF or normal LA size (32,34). Our meta-analysis further underscored the additional prognostic implication of evaluating LA mechanics in clinical management, overcoming the limitations of LVEF.…”

Incremental prognostic value of left atrial strain in patients with heart failure

“…24,25 Depletion of compensatory mechanisms translates into overt HF or deteriorated clinical condition. 26 In the advanced stage of HF, LA is enlarged and remodelled to varying degrees with impaired function, which is usually associated with chronic and severe symptoms. 27,28 With the progression of HF, atrial dysfunction may be a late consequence of systemic and pulmonary circulatory changes caused by HF.…”

“…Previous studies suggested that abnormal LA function in the early stages of HF is an early indicator of LV diastolic dysfunction 24,25 . Depletion of compensatory mechanisms translates into overt HF or deteriorated clinical condition 26 . In the advanced stage of HF, LA is enlarged and remodelled to varying degrees with impaired function, which is usually associated with chronic and severe symptoms 27,28 .…”