Work-up and management of patients with paradoxical emboli

Paradoxical embolism is defined as the passage of any material from the venous circulation into the systemic arterial tree via an abnormal communication which is accompanied by a right-to-left shunt. Although there are fewer than 40 reported cases, its incidence is probably much more frequent. This article describes our experiences treating six patients at Charleston Area Medical Center whose diagnosis of paradoxical emboli was based on the presence of Johnson's triad: (1) Venous thrombosis with/without pulmonary embolism, (2) An intracardiac defect with right-to-left shunting; and (3) Arterial embolism without a corresponding source in the left heart or proximal arterial tree. We conclude that paradoxical embolism should be considered in all patients with an unknown source of emboli, particularly young patients. If conventional M + 2D echocardiography and peripheral angiography are inconclusive, further work-up should be performed with contrast saline echocardiography, transesophageal echocardiography, lung scan, and peripheral venous imaging.