Left Atrium

Abstract

The left atrium is a critical cardiac structure. Abnormalities in left atrial function affect not only left ventricular function but also predict poor cardiovascular outcomes. Depending on the population, increased rates of atrial fibrillation, stroke and hospitalization have been associated with increased left atrial size. The left atrium is best assessed with transthoracic echocardiography using dedicated two-dimensional imaging views. While three-dimensional echocardiography-derived volumes are more accurate, current use is limited by lack of normal values and automated analysis packages that allow rapid measurement in clinical practice. Available left atrial cut-offs are based on maximum volumes indexed for body-surface area and do not differ between genders. While much of the available data is on maximum left atrial volume, other measurements may provide more important information on pathological processes and better prognosticate outcomes. These measurements include: changes in left atrial volumes during the cardiac cycle; left atrial contractile function measured through strain; and left atrial shape. Finally, monitoring of left atrial changes and recognition of reverse remodelling may lead to the use of left atrium as therapeutic target in clinical practice and trials.