CASE PRESENTATION: A 19 year old male with no past medical history was brought to the ER after developing new onset seizures at home. Vital signs on presentation included heart rate of 113 beats/minute, blood pressure of 95/58, and pulse oximetry of 87% on room air that quickly normalized. Physical examination including his neurologic status was unremarkable. Workup included a normal head CT, EEG, with subsequent admission to Neurology. The next morning, a repeat generalized tonic-clonic seizure resulted in refractory hypotension, tachycardia, and hypoxemia, prompting a critical care evaluation. The EKG revealed right ventricular strain and a S1Q3T3 finding. On chart review, patient had an elevated D-dimer to 3.28 ng/mL on admission, all raising the suspicion for thromboembolic disease. Stat bedside echo demonstrated RV dilatation and poor function. Subsequent ultrasound of the lower extremities diagnosed acute thrombus. During the workup, he developed further hypotension and hypercapnic respiratory failure requiring intubation that deteriorated to cardiopulmonary arrest. During ACLS, emergent Tissue Plasminogen Activator was administered in addition to cardioversion for supraventricular tachycardia with ROSC after 10 minutes. Repeat bubble echo revealed normal RV function without shunt physiology. Patient was discharged with intact neurologic function 12 days later.