The Role of the Left Atrium: From Multimodality Imaging to Clinical Practice: A Review

Abstract

In recent years, new interest is growing in the left atrium (LA). LA functional analysis and measurement have an essential role in cardiac function evaluation. Left atrial size and function are key elements during the noninvasive analysis of diastolic function in several heart diseases. The LA represents a “neuroendocrine organ” with high sensitivity to the nervous, endocrine, and immune systems. New insights highlight the importance of left atrial structural, contractile, and/or electrophysiological changes, introducing the concept of “atrial cardiomyopathy”, which is closely linked to underlying heart disease, arrhythmias, and conditions such as aging. The diagnostic algorithm for atrial cardiomyopathy should follow a stepwise approach, combining risk factors, clinical characteristics, and imaging. Constant advances in imaging techniques offer superb opportunities for a comprehensive evaluation of LA function, underlying specific mechanisms, and patterns of progression. In this literature review, we aim to suggest a practical, stepwise algorithm with integrative multimodality imaging and a clinical approach for LA geometry and functional analysis. This integrates diastolic flow analysis with LA remodelling by the application of traditional and new diagnostic imaging techniques in several clinical settings such as heart failure (HF), atrial fibrillation (AF), coronary artery disease (CAD), and mitral regurgitation (MR).

Is It Possible to Predict False-Positive Exercise Stress Echocardiography Results by Measuring the Left Atrial Antero-Posterior Diameter?

“…The relation of LA enlargement with the risk of cardiovascular death may be partially mediated by increased LV mass. The increase in myocardial mass lowers coronary reserve, enhances cardiac oxygen requirements, and impairs LV filling and contractility [1,57].…”

Evolving Applications of Echocardiography in the Evaluation of Left Atrial and Right Ventricular Strain

“…Other imaging modalities for LA assessment include cardiac magnetic resonance (CMR) and cardiac computed tomography (CCT). In addition to LA anatomy and function, CMR is also able to assess LA fibrosis from late gadolinium enhancement (LGE) [ 7 , 8 ]. CCT also permits the evaluation of pulmonary venous anatomy [ 9 ], estimation of risk of AF recurrence, and coronary artery disease [ 8 ].…”

Targeting left atrial dysfunction: A new way to prevent cardiovascular disease?

“…6 The study of atrial function has been hindered for a long time by a series of factors linked primarily to the complexity of LA anatomy (more variable than the left ventricle and its asymmetric wall) and physiology (i.e., reservoir function, conduit function, booster pump). 7 LA reservoir function reflects the ability of the LA to store pulmonary venous return during LV contraction and isovolumetric relaxation. Conduit LA function represents the ability to passively transfer blood into the LV.…”