Paradoxical embolism: A case of thromboembolic stroke secondary to pulmonary embolism and deep vein thrombosis

Paradoxical embolism refers to thromboemboli originating from the venous system or right heart that traverse an intracardiac or pulmonary shunt into the systemic circulation, causing end-organ embolization. It is hypothesized to occur when the right atrial pressure exceeds the left atrial pressure. To date, patent foramen ovale is the most common intracardiac shunt associated with paradoxical embolism. During acute pulmonary embolism, acutely elevated right atrial pressure can reopen a functionally closed patent foramen ovale, facilitating paradoxical embolism into the systemic circulation. The cerebrum is the most frequently affected organ, resulting in neurological deficits, followed by peripheral arterial occlusion and mesenteric embolism; myocardial infarction is rarely reported. Herein, we describe the diagnosis and management of a patient in her early 60s who presented with acute cerebral embolism caused by paradoxical embolism complicating acute pulmonary embolism.