Right-to-left atrial shunt in cardiac dislocation following extensive pneumonectomy

Previous reports dealing with cardiac herniation following intrapericardial pneumonectomy illustrate the critical and often lethal hemodynamic sequelae of this complication. In the case presented here, the first and nearly exclusive sign of cardiac herniation after left-sided pneumonectomy with extensive resection of the pericardium was systemic arterial hypoxemia. Subsequent investigations suggested inter-atrial right-to-left shunt in the presence of a patent foramen ovale, caused by slight right-ventricular outflow obstruction with consecutively reversed pressure relationships at atrial level. This explanation was supported by the operative findings, and reversibility was achieved by pericardial reconstruction with parietal pleura. When the patient died 8 months later due to general progression of a mucoepidermoid carcinoma, autopsy confirmed a large patent foramen ovale.