Anatomy of the Left Atrial Appendage

Atrial fibrillation (AF) increases the risk of stroke and peripheral embolism-related deaths. The left atrial appendage (LAA) is a remnant of embryonic development and embryologically derived from the primitive atrium. The LAA presents with diverse shapes, and its morphology can differ from one individual to another. Morphologic analysis becomes particularly crucial during the planning phase of interventional procedures for left atrial appendage occlusion (LAAO) as a non-pharmacologic means of stroke prevention in the settings of atrial fibrillation. The goal of LAAO is the complete exclusion of the LAA. Due to variable anatomy, device selection needs careful attention for safe and successful procedural outcomes. LAAO is appropriate for non-valvular AF patients with high thromboembolic risk and contraindication for long-term oral anticoagulation, Class IIa. Morphologic LAA analysis is critical during the planning phase of interventional procedures for LAAO. In some cases, complications may arise in periprocedural settings due to interaction with anatomical structures and should be addressed accordingly.