Atrial masses are rare and more often localized in the right atrium. They are usually detected incidentally, and the leading causes are tumors, thrombi, or infective vegetations. However, normal structures and artifacts ("pseudomasses") should also be considered in differential diagnosis, especially after cardiac and/or aortic surgery. We present a case of an unusual left atrial image observed on transthoracic echocardiography in an 83-year-old woman after an intervention of open-chest ascending aorta replacement and myocardial revascularization.