Percutaneous left atrial appendage (LAA) closure is an emerging technology for thromboembolic prevention in patients with atrial fibrillation (AF). The first human implantation of an LAA device occurred in 2001, and since then four devices have received CE mark approval. These devices are being widely used in Europe for LAA closure in patients who are poor candidates for long-term oral anticoagulation. In the US, the WATCHMAN device (Boston Scientific)...