Delayed hemopericardium following penetrating foreign body into the aorta.

A four and a half year old girl with delayed appearance of traumatic hemopericardium, detected radiologically despite misleading clinical manifestations, is presented. The presence of cardiomegaly and a needle in the right upper mediastinum on the chest roentgenogram and its partial motion together with diminished cardiac pulsations at fluoroscopy led to angiocardiography. The radiological demonstration of hemopericardium due to the needle penetrating the aortic root, enabled successful surgical intervention.