The Left Atrial Appendage Ostium: Hotspots for Localized Re-Entry

LAA ATs are almost always micro-re-entrant in mechanism and originate from either the anterior base or LAA ridge. AT originating from inside the LAA body is very rare. The anterior and ridge aspects of the LAA-left atrium junction seem to be arrhythmogenic hotspots prone to localized re-entry. These ATs are treatable with focal ablation without LAA isolation but are frequently associated with macro-re-entrant peri-mitral flutter.