Clinical Snapshot
Left Atrial Septal Pouch as a Potential Source of Embolism
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A 74-year-old patient with dilated cardiomyopathy and atrial fibrillation suffered an ischemic stroke with hemiparesis. As part of the search for the cause, transesophageal echocardiography (TEE) revealed a large, mobile structure originating from the left atrial septal pouch (LASP) (Figure). Prior to surgical resection, the structure was no longer detectable on intraoperative TEE. Further evaluation identified occlusion of the right common femoral artery. Embolectomy and histopathological evaluation confirmed thromboembolism. The patient was ultimately discharged with oral anticoagulation therapy. The LASP is an anatomical variant first described in 2010 that results from incomplete fusion of the septum primum and septum secundum, thereby forming a “pouch” on the left atrial septum. To meet diagnostic criteria, interatrial communication must be excluded by contrast-enhanced TEE. This little-known “pouch,” often overlooked on TEE, is a potential site of blood stasis and thrombus formation and should be considered a hitherto underestimated cardiac source of embolism in patients with stroke or systemic embolism.
Dr. med. Ali Hamadanchi, Klinik für Innere Medizin I (Kardiologie, Internistische Intensivmedizin, Angiologie), Universitätsklinikum Jena, Friedrich-Schiller-Universität, Jena, ali.hamadanchi@med.uni-jena.de
Dr. med. Albrecht Günther, Klinik für Neurologie, Universitätsklinikum Jena, Friedrich-Schiller-Universität, Jena
Dr. med. Maximilian Nicolas Möbius-Winkler, Klinik und Poliklinik für Kardiologie, Universitätsklinikum Leipzig AöR, Leipzig
Conflict of interest statement: AG received speaker’s fees from Boehringer Ingelheim, Shionogi, Daiichi Sankyo, Pfizer, and Ipsen, as well as research funding from Boston Scientific and Ipsen Pharma. MNMW received speaker’s fees from Bristol Myers Squibb. AH declares that no conflict of interest exists.
Translated from the original German by Christine Rye.
Cite this as: Hamadanchi A, Günther A, Möbius-Winkler MN: Left atrial septal pouch as a potential source of embolism. Dtsch Arztebl Int 2026; 123: 262. DOI: 10.3238/arztebl.m2025.0246
