Atrial septal defect paradoxical emboli


 * Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S. [mailto:psingh@perfuse.org]; Assistant Editor(s)-In-Chief: Kristin Feeney, B.S. [mailto:kfeeney@perfuse.org]

Overview
Normally the emboli originating from the venous thrombus goes to the lung leading to pulmonary complications. However, in patients with atrial septal defects, a emboli can enter the arterial system through the defect. This may lead to rare complications like stroke and migraine. However, these defects are more common in patent forman ovale compared to atrial septal defect.

Paradoxical emboli
Venous thrombi (clots in the veins) are quite common. Embolization (dislodgement of thrombi) normally go to the lung and cause pulmonary emboli. In an individual with ASD, these emboli can potentially enter the arterial system,. This can cause any phenomenon that is attributed to acute loss of blood to a portion of the body, including cerebrovascular accident (stroke), infarction of the spleen or intestines, or even a distal extremity (i.e.: finger or toe).

This is known as a paradoxical embolus because the clot material paradoxically enters the arterial system instead of going to the lungs.