Abstract 14201: Double the Trouble: Extremely Rare Incidental Finding of a Double Interatrial Septum With Atrial Septal Aneurysm and Coexisting Patent Foramen Ovale

• DOI: 10.1161/circ.148.suppl_1.14201
• Publication Date: 2023-12-19T07:59:21Z
• Authors: Vishnu Bharani; Kevin Tang; Kavin Krishnam; Deniz Urgun; Ali Naqvi
• Keywords: Interatrial septum; Palpitations; Primary interatrial foramen; Fossa ovalis; Foramen ovale (heart); Transesophageal echocardiogram; Septum secundum

Case: A 59-year-old female with a past medical history of hypothyroidism and IgG deficiency presents to cardiology clinic due palpitations premature ventricular complexes (PVCs) noted at recent urgent care visit. In-office vitals, physical exam, labs, EKG were unremarkable. Ambulatory cardiac monitoring showed predominantly sinus rhythm PVC burden 1.4%. Echocardiogram revealed an extremely rare structural anomaly – double interatrial septum (DIAS) atrial septal aneurysm. Cardiac MRI (cMRI) further confirmed the presence DIAS enclosing space, along blood flow within space discontinuity in anterior right lateral suggestive patent foramen ovale (PFO). There was no evidence thrombus or intracardiac spaces. Mild enlargement seen. The patient initiated on aspirin for cardioembolic stroke prophylaxis. Discussion: is highly congenital limited number cases literature. It has been described as midline third atrium resulting “tri-atrial heart”. As 2018, less than 20 have cited. characterized by two parallel septa clear echo lucent that expands systole collapses diastole. This case unique it one few include additional characterization cMRI. Patients are usually asymptomatic but can experience events risk formation. Communication across makes these more likely. Unlike fibrillation/flutter, current criteria anticoagulation (AC) initiation exists given scarcity cases. While some sources advocate use anti-platelet agents, others indicated preference oral AC. Our had PFO lacked communication DIAS, low bleeding risk, other classic factors Virchow’s triad. We determined her formation be relatively low, thus over Percutaneous closure deferred dismissed viable treatment option