Left atrial appendage closure.

Stroke or systemic embolism is a devastating consequence of atrial fibrillation (AF) due to thrombus formation in the left atrial appendage (LAA). AF causes thrombus formation in the LAA due to both the loss of atrial systole and the unique anatomic features of the LAA. Oral anticoagulation is a well established and effective therapy to reduce the risk of stroke in AF patients, albeit with a risk of bleeding. LAA closure is a possible alternative to oral anticoagulation in the prevention of stroke or systemic embolism in AF.