Large serpiginous thrombus straddling the patent foramen ovale and traversing through mitral and tricuspid valves into both ventricles: a therapeutic dilemma of impending paradoxical embolism and recurrent pulmonary embolism.

A 51-year-old male with history of resected renal cell carcinoma and prior pulmonary embolism presented with tachypnea, tachycardia and progressive dyspnea on exertion. Chest computed tomography revealed bilateral acute pulmonary embolism. Transthoracic echocardiogram showed severe pulmonary hypertension with severe cor-pulmonale and presence of a large worm-like thrombus extending across the foramen ovale, entering both ventricles through the mitral and tricuspid valves. The risks of anti-coagulation, pharmacologic thrombolysis, and surgical thrombectomy, in a hemodynamically stable patient, posed a significant therapeutic dilemma. Ultimately, a collective decision was made to start anticoagulation, without incident. At 1 month follow up, complete resolution of the intracardiac thrombus, pulmonary hypertension, and cor-pulmonale were observed with full clinical recovery of the patient.