title: The left atrial appendage: anatomy, function, and noninvasive evaluation.
abstract: The left atrial appendage (LAA) is a finger-like extension originating from the main body of the left atrium. Atrial fibrillation (AF) is the most common clinically important cardiac arrhythmia, occurring in approximately 0.4% to 1% of the general population and increasing with age to >8% in those >80 years of age. In the presence of AF thrombus, formation often occurs within the LAA because of reduced contractility and stasis; thus, attention should be given to the LAA when evaluating and assessing patients with AF to determine the risk for cardioembolic complications. It is clinically important to understand LAA anatomy and function. It is also critical to choose the optimal imaging techniques to identify or exclude LAA thrombi in the setting of AF, before cardioversion, and with current and emerging transcatheter therapies, which include mitral balloon valvuloplasty, pulmonary vein isolation, MitraClip (Abbott Laboratories, Abbott Park, Illinois) valve repair, and the implantation of LAA occlusion and exclusion devices. In this review, we present the current data regarding LAA anatomy, LAA function, and LAA imaging using the currently available noninvasive imaging modalities.
authors.affiliation: The Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California; The Heart Institute, Sheba Medical Center, and the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Roy
authors.initials: R
authors.lastname: Beigel
authors.affiliation: Cardiovascular Center Darmstadt, Darmstadt, Germany.
authors.forename: Nina C
authors.initials: NC
authors.lastname: Wunderlich
authors.affiliation: Cardiac Morphology Unit, Royal Brompton Hospital, London, England.
authors.forename: Siew Yen
authors.initials: SY
authors.lastname: Ho
authors.affiliation: The Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California.
authors.forename: Reza
authors.initials: R
authors.lastname: Arsanjani
authors.affiliation: The Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California. Electronic address: Robert.siegel@cshs.org.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Siegel
mesh_terms: D000818:Animals; D020517:Atrial Appendage / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000503:physiopathology; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy; D002932:Cineangiography; D003952:Diagnostic Imaging / Q000379:methods; D004452:Echocardiography; D006801:Humans; D011237:Predictive Value of Tests; D018570:Risk Assessment; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: anatomy; function; left atrial appendage; noninvasive imaging; thromboembolism