ABSTRACT
Stroke is the most feared complication in patients surviving a cardiovascular event and occurs with an incidence of approximately 780,000 cases per year in the United States. Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is increasing in frequency as the population ages. Multiple sources of data, including pathological and echocardiographic studies, have documented that the left atrial appendage (LAA) is the site of thrombus formation in approximately 90" of patients with nonvalvular AF. Assessment of the specific details of LAA anatomy is essential for patient selection and procedural performance. Approaches to closure of the LAA include endovascular approach via transseptal puncture to plug the appendage, and epicardial approaches, either surgical or percutaneous. Approaches to the transseptal catheterization vary considerably and have evolved over time. The goal for left appendix exclusion is to cross the atrial septum at the level of the fossa ovalis.
