Introduction: Saddle pulmonary embolism (PE) is characterized by a thrombus lodged at the bifurcation of the main pulmonary artery and can lead to significant hemodynamic compromise. We describe a rare case of a saddle pulmonary embolus with an extension of the thrombus from the right atrium into the left atrium through a patent foramen ovale (PFO).
Description: A 75-year-old man with a history of a previous unprovoked PE over a decade ago, diabetes mellitus, hyperlipidemia and hypertension, presented with visual loss in his left eye, there were no other concurrent symptoms including syncope or dyspnea, or a recent travel history. Initial brain imaging showed multifocal infarcts with asymptomatic petechial hemorrhage in the occipital lobe, contraindicating systemic thrombolytics. An echocardiogram demonstrated a highly mobile thrombus transversing the interatrial septum. A doppler ultrasound showed a partially occlusive thrombus in the left popliteal vein. He was initiated on anticoagulation with heparin after careful discussion with neurology and hematology.
The computed tomography scan of the chest demonstrated saddle PE with extensive thrombus throughout both lungs, and a large thrombus in the right ventricle and right atrium extending through a PFO into the left atrium and without evidence of right heart strain. Additionally, there was a large acute infarct within the spleen, likely embolic in origin. He underwent a successful intracardiac and pulmonary artery embolectomy with surgical PFO closure. His post-op course was unremarkable and he was discharged from hospital post-op day 5 in stable condition with continuation of lifelong anticoagulation therapy.
Discussion: This is a unique presentation of a PE with a thrombus extending through a PFO into the left atrium. It is also interesting in the fact the patient presented with a stroke and did not have dyspnea or noted hypoxemia in spite of a saddle PE with extensive bilateral segmental clot burden. Furthermore, given a quite rare presentation of PE with extension into the left atrium and concurrent embolic phenomena, radiologists and treating physicians need to be aware of the possibility of clot migration through a PFO.
