744 LEFT ATRIAL DISSECTION AFTER MITRACLIP IMPLANTATION: ECHOCARDIOGRAPHIC FEATURES

Abstract

Abstract Introduction the MitraClip system (MC) is the leading transcatheter technique to treat mitral regurgitation (MR), presenting very low adverse event rates. Left atrial dissection (LAD) is defined as a gap from left atrial wall. Aim we report a case of LAD occurring after MC implantation, treated conservatively, focusing on suggestive echocardiographic features. Materials and methods transthoracic and transesophageal echocardiography with 3D reconstructions were performed. Results the patient was a 73-years-old woman with symptomatic severe MR due to flail leaflet, treated with MC. Seven days later, the echocardiography showed a large mass in the left atrium not visible previously, initially thought to be a thrombus. Further investigation using transoesophageal echocardiography showed a large formation, with uneven echogenicity, at the level of the left atrium without signs of obstructing mitral valve inflow. 3D-rendering was also performed, revealing an echolucent area between the endocardium and the left atrial free wall, presenting increase echogenicity portions, suggestive of being LAD with partial thrombosis inside. The patient was treated with unfractionated heparin and after six days the echocardiogram showed complete resolution of thrombotic elements, with residual double-track linear hyperechoic formation within the atrial posterior wall, identifying an anechoic space. Therefore, the echocardiographic features suggested the diagnosis of left atrial intramural hematoma, initially thrombosed, then dissolved. Conclusions LAD is a rare complication either of cardiosurgical and transcatheter procedures. Both operator awareness and imaging features are important for diagnosis. 3D rendering can be useful in the early differential diagnosis, facilitating an optimal management.