Left Atrial Appendage Sludge vs. Thrombus: Can Echocardiography Distinguish Them?

Left atrial appendage sludge or clot: Sludge appears as heterogeneous material that moves with blood flow, has a granular appearance, and does not conform to the shape of the appendage. It can resolve spontaneously and change over time. True clot is uniform, more echogenic, and stationary within the LAA, adhering to the walls. It is persistent and stable, due to fibrin cross-linking and attachment to the endocardial surface.