In collaboration with the Consulting Editors, Ranjan K. Thakur and Andrea Natale, Drs. Dhanunjaya Lakkireddy, David R. Holmes Jr., and Saibal Kar have assembled an issue of Cardiac Electrophysiology Clinics on Left Atrial Appendage. Topics include, but are not limited to, why we have an atrial appendage, thromboembolism in AF, role of LAA in systemic homeostasis, history of LAA closure, impact of LAA closure on systemic thromboembolization, perirprocedural imaging, anatomical considerations for epicardial and endocardial appendage closure, epicardial vs endocardial closure, technical considerations of endocardial and epicardial closure, surgical LAA occlusion, post procedural management, AF patients undergoing ablation, and more.