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A5336 - A Rare Case of Paradoxical Embolization During Thrombolysis for a Pulmonary Embolus
Author Block: M. Onwochei-Ashei1, W. McGee1, M. A. Tidswell2, P. Mailloux1; 1Critical Care Medicine, Baystate Medical Center, Springfield, MA, United States, 2Baystate Med Ctr, Springfield, MA, United States.
Introduction Paradoxical embolization occurs when an embolus formed in the systemic venous circulation enters the systemic arterial circulation via an intracardiac shunt in the presence of a right-to-left atrial pressure gradient. The most common intracardiac shunt is a patent foramen ovale (PFO) which is present in approximately 25 percent of adults.[1] Clinical Vignette A 42-year-old woman with a past medical history of provoked Deep Vein Thrombosis (DVT), morbid obesity, Chronic Obstructive Pulmonary Disease, active smoker presented with pleuritic chest pain. She was found to have low systolic blood pressure of 82, heart rate of 134, respiratory rate of 26 and oxygen saturation of 78. Computed tomographic angiography (CTA) of her chest revealed extensive bilateral pulmonary emboli (P.E). Given her hemodynamic instability, Tissue Plasminogen Activator (tPA) was infused. During tPA administration, she developed aphasia, right gaze palsy, right hemiparesis and confusion. Emergent CTA of her head and neck showed no hemorrhage but did reveal occlusion of the left proximal M2 branch. Her stroke symptoms improved within 1 hour. An echocardiogram with agitated saline contrast revealed a PFO. A DVT sonogram revealed a partially occlusive thrombus in the right common femoral vein. She was treated with unfractionated heparin (UFH) and transitioned to warfarin prior to hospital discharge. Discussion Paradoxical emboli are rare life-threatening events and account for 2% of arterial emboli.[2] Conditions (such as a P.E) can cause an increase in right atrial pressure which in the presence of an intracardiac shunt, can lead to right-to-left shunt with passage of venous emboli into the arterial system. Contrast echocardiography will reveal an intracardiac shunt. Treatment often includes anticoagulation therapy (in patients with venous thromboembolism) or antiplatelet therapy (in patients with stroke), and PFO closure (in stroke patients less than 60 years old with a noted right-left shunt).[3] Paradoxical embolism is rarely recognized and remains underreported despite its potentially lethal complications. We present a patient with a rare case of paradoxical embolization whilst undergoing going tPA. Case reports such as this will help raise awareness of this rare disease entity.
References[1] Meissner et al. Prevalence of potential risk factors for stroke assessed by transesophageal echocardiography and carotid ultrasonography. Stroke Prevention: Assessment of Risk in a community. Mayo Clin Proc. 1999. [2] Carvalho et al. Paradoxical peripheral embolism - A Rare and Underestimated Event. ScienceDirect. 2009 [3] Saver et al. Long-Term Outcomes of Patent Foramen Ovale Closure of Medical Therapy after Stroke. NEJM. 2017.