P113 HIDDEN POCKET. LEFT ATRIAL SEPTAL POUCH: VARIANT OF NORMALITY OR CARDIOEMBOLIC SOURCE?

Abstract

Abstract During embryological period the blood flows from right to left atrium trought patent interatial septum. Embryon’s interatrial semptum consists on the apposition of Septum Secundum (SS) over Septum Primum (SP) that go to seal each other just afther birth. Sometimes this fusion doesn’t happen or partially happens, leading respectively to patent foramen ovale (PFO) or the less known eventuality of Atrial Septal Pouch (ASP). 48–year–old woman, history of chronic anemia treated with blood transfusions, underwent a routine transthoracic echocardiogram (TTE) as recommended by her transfusion center. The patients is asymptomatic, denies cardiovascular risk factors, denies any signs or symptoms suggestive of recent infectious or inflammatory disease. The TTE documented preserved left ventricular sistolic function, normal sized cardiac chembers, no valvular abnormalities, evidence of linear formation (10 x 5 mm), near foramen ovale, on the left side of interatrial septum, increased in echogenicity. It was performed a transesophageal echocardiogram (TEE) which confirmed the finding at SIA level. It was therefore recommended in depth study with cardiac magnetic resonance (CMR) which described the same mobile formation, characterized by the same signal strength as the atrial walls, both before and afther contrat administration, compatible in the first hypotesis with an embryonic residue (Left Atrial Septal Pouch, LASP). There is still much uncertainty regarding the clinical significance of LASP, however, its large prevalence among general population suggests that its potential embolism requires other predisposing conditions in order to be of real clinical relevance. CMR represents a usefull test for cardiac structures analysis owing its better tissue characterization cormpared to other diagnostic tests. In the event of an occasional finding and in absence of any other indication for anticoagulant therapy, no therapeutic measures are currently indicated. These patients could be followed up in order to promptly identify the onset of prothrombotic conditions likely to expose them to higher risk compared with patients who do not have LASP.