Anatomy, Thorax, Heart Left Atrial Appendage

The left atrial appendage (LAA) is a unique structure within the pericardium, close to the free wall of the left ventricle. It has unique developmental, structural, and physiological characteristics that separate it from the left atrium proper. In normal cardiac physiology, the LAA plays an essential role in regulating intravascular volume by releasing natriuretic peptides in response to hemodynamic changes. The LAA also plays a vital role in the pathogenesis of transient ischemic attack (TIA) and stroke in patients with atrial fibrillation (AF).