Delayed intracardial shunting and hypoxemia after massive pulmonary embolism in a patient with a biventricular assist device

We describe the interdisciplinary management of a 34-year-old woman with dilated cardiomyopathy three months postpartum on a cardiac biventricular assist device (BVAD) as bridge to heart transplantation with delayed onset of intracardial shunting and subsequent hypoxemia due to massive pulmonary embolism. After emergency surgical embolectomy pulmonary function was highly compromised (PaO(2)/FiO(2) 54) requiring bifemoral veno-venous extracorporeal membrane oxygenation. Transesophageal echocardiography detected atrial level hypoxemic right-to-left shunting through a patent foramen ovale (PFO). Percutaneous closure of the PFO was achieved with a PFO occluder device. After placing the PFO occluder device oxygenation increased significantly (Delta p(a)O(2) 119 Torr). The patient received heart transplantation 20 weeks after BVAD implantation and was discharged from ICU 3 weeks after transplantation. An increase in pulmonary vascular resistance in patients on BVAD can reopen a PFO resulting in atrial right-to-left shunting and subsequent hypoxemia. The case demonstrates the usefulness of transesophageal echocardiography examinations in the detection of this unexpected event. Percutaneous placement of a PFO occluder device is an appropriate strategy to stop intracardiac shunting through PFO in fixed elevation of pulmonary vascular resistance