A coronary embolus originating from the interatrial septum

A 25-year-old woman was admitted for recurring left-sided chest pain of increasing intensity since 2 h. The initial ECG was unremarkable, but troponin I levels were elevated (2.2 µg/L). Thrombotic occlusion of the left circumflex artery was diagnosed by coronary angiography and sucessfully recanalized. Transthoracic echocardiography showed normal global left ventricular function with hypokinesia of the posterobasal segment. Transoesophageal echocardiography (TEE) demonstrated a double-layered interatrial septum, probably due to a remnant septum primum, forming a cavity between the two septal layers and an enclosed thrombus-like mass (0.5×0.6 cm, Panel A). The presence of a cavity within the interatrial septum was verified by magnetic resonance imaging (Panel C, arrow). Active smoking and hormonal contraception were the only identifiable thrombophilic risk factors. After 3 days of therapeutic anticoagulation, a repeat TEE exam showed complete resolution of the thrombus (Panel B) and no evidence for a patent foramen ovale with injection of a right-heart echo contrast agent. Injection of a left-heart contrast agent (Levovist®, Schering, Berlin, Germany) demonstrated perfusion of the interatrial septal cavity from the left atrium (Panel D). The presented case demonstrates a rare, previously unrecognized cause for thrombus formation within the interatrial septum in the absence of a patent foramen ovale and for peripheral embolism. See Supplementary Data available at European Heart Journal online. Panel A. Cavity between the two layers and a thrombus-like mass. Panel B. Complete resolution of the thrombus. Panel C. Magnetic resonance imaging. Panel D. Perfusion of the interatrial septal cavity from the left atrium.