Left atrial myxoma presenting as pulmonary embolism: potential role of heme oxygenase-1.

We present the case of a patient with left atrial myxoma that presented with pulmonary embolism. The patient did not have any intracardiac communication between right and left sides of the heart. Using thrombelastography, the patient was determined to have an abnormally large velocity of plasma thrombus growth and strength with reduced vulnerability to lysis. Critically, increased carboxyhemoglobin concentrations were present, likely secondary to hemolysis from the tumor and engagement of systemic heme oxygenase-1. It was determined that the patient's plasmatic hypercoagulability was in part due to carboxyhemefibrinogen formation via a thrombelastographic method. In addition to circulating hypercoagulability, the patient also had an area of chronic venous stasis in his left ankle that had not changed for over a decade prior to this thrombophilic episode. In conclusion, we present the first case of paradoxical pulmonary embolism in the presence of a left atrial myxoma, potentially secondary to a combination of hemolysis, heme oxygenase-1 up-regulation, systemic hypercoagulability/hypofibrinolysis, and regional venous stasis.