Postural Conversion Computed Tomography for the Diagnosis of Pneumopericardium due to Perforation by the Active Atrial Lead

A 71-year-old woman with cardiac sarcoidosis underwent an implantable cardioverter-defibrillator implantation in the left precordium to prevent fatal arrhythmias. Two weeks later, she presented with dyspnea. Chest X-ray revealed right pneumothorax due to the active atrial lead perforation. Subsequently, air was detected surrounding the heart. Although it was difficult to differentiate pneumopericardium from pneumomediastinum, postural conversion computed tomography (CT) in the supine and prone positions documented air migration in the pericardial cavity and diagnosed pneumopericardium. This rare case of pneumopericardium combined with pneumothorax contralateral to the venous access site highlights the utility of postural conversion CT for diagnosis of pneumopericardium.