Proposed pathophysiology of left atrial appendage thrombus formation. Several anatomical, cellular, and physiological features contribute to thrombus formation within the left atrial appendage. Of note, different thromboembolic risk might be attributed to anatomic configurations of the left atrial appendage⁷ as well as flow and fluid dynamics.^8,9 LAA, left atrial appendage; EC, endothelial cell; eNOS, endothelial nitric oxide synthase; NO, nitric oxide; NOS, nitric oxide synthase; PGI₂, prostaglandin I2; ROS, reactive oxygen species; TXA₂, thromboxane A2; vWF, von Willebrandt factor; arrows indicate increase or decrease.