LA/LAA Clot Classification Left Atrial (LA) and Left Atrial Appendage (LAA) Thrombus Classification Introduction Left atrial (LA) and left atrial appendage (LAA) thrombi are major sources of cardioembolic stroke, particularly in patients with Atrial Fibrillation, mitral valve disease, heart failure, and severe left atrial enlargement. Accurate characterization of thrombus morphology is important because thrombus size, mobility, and attachment influence embolic risk and procedural planning for cardioversion, catheter ablation, and LAA closure. Although no universally accepted classification system exists, LA/LAA thrombi are commonly categorized according to morphology, mobility, location, and chronicity. --- 1. Classification by Morphology Type I: Pedunculated (Mobile) Thrombus Attached to the atrial wall or LAA by a narrow stalk. Exhibits marked mobility during the cardiac cycle. Highest embolic potential. Can occasionally mimic an atrial myxoma. Clinical significance: Immediate a...