IDIOPATHIC ENLARGEMENT OF THE RIGHT ATRIUM

A case of aneurysmal enlargement of the right atrium was found acciden tally during a routine examination, The patient was asymptomatic and f ree of palpitations or proven rhythm disturbances. The results of echo cardiography, magnetic resonance imaging, and cardiac catheterization excluded cardiac malformation, which could have caused secondary enlar gement of the right atrium. A partial pericardial defect as a likely c ause of herniation of the right atrium was ruled out by magnetic reson ance imaging. In keeping with these results, isolated aneurysmal enlar gement of the right atrium was diagnosed.