The results confirm that percutaneous interventional perforation is an effective first-stage procedure in patients with pulmonary atresia with intact ventricular septum. The right heart appeared to be adequate to maintain a long-term biventricular circulation in the large majority of cases.

Summary: Pericardial cysts are usually detected by chance and are clinically silent in most cases. Nevertheless, symptoms and serious complications may occur. We describe a case of pericardial cyst diagnosed in an 8-year-old boy who was admitted with chest pain. Echocardiography revealed a mild to moderate pericardial effusion and a 7.5 X 5.5 cm intrapericltrdial echo-free lesion consistent with a pericardial cyst. Surgery was carried out 3 days afterward because of the patient's worsening condition, the progressive increase of pericardial effusion, and the onset of initial signs of cardiac tamponade. The cyst showed a long and easily movable vascular pedicle and inflammatory areas involving the pericardial surfxc. Like the pericardial effusion, the contents of the mass appeared as serosanguineous fluid on aspiration. Histologic examination confirmed the diagnosis of pericardial cyst and showed findings according to ischemia-related lesions of the cyst. The coexistence ofpericardial cyst and cardiac tamponade is very unusual. The atypical anatomy and clinical course suggest a distinct and so far undescribed pathogenetic mechanism for this association: the torsion of a vascularpedicle and the subsequent development of ischemia-related lesions ofthe cyst.