Characteristics of LAA in children
The LAA is the remnant of the original embryonic left atrium that
develops during the third week of
gestation8, so it is a
structure anatomically appended to the main body of the LA, which locate
between the left upper pulmonary vein and the left ventricle. The LAA
has a wide perimeter that interfaces with the atrial
musculature4. In the
LAA, thick cords of pectinate muscle intervene with thin-walled
tissue8. The anisotropic
junctional tissue, with a complex fiber orientation, results in
electrophysiological properties that may predispose this region to be
the source of the
arrhythmia3.
In children, left atrium in size is small, and increase as ages. The LAA
lies within the confines of the pericardium, and thus its emptying and
filling may be affected by left ventricular function.