Left atrial function

Abstract

The objective of studying left atrial (LA) function is to understand its contribution to the overall stroke volume as well as to find methods for estimating LA pressure as a cause of breathlessness. LA shares many anatomical features of the left ventricle (LV), and orientationally, it is a mirror image of the latter. Although the overall myocardial thickness of LA is only one-third that of LV, basal myocardial fibers of LA are circumferential and the rest of the myofibers are longitudinal, originating from the back of the atrium, being attached to the mediastinal ligaments, and inserting in the mitral annulus. Such anatomical design makes LA and LV functionally interdependent, with systole of one chamber occurring during diastole of the other and vice versa. LA function encompasses the following components; reservoir, electric, electromechanical and mechanical. Each of these components plays an important role in maintaining the overall normal function of the chamber, despite the age-related changes that have significant functional implications (1).