Unusual Effect of an Atrial Septal Aneurysm on Venous Drainage During Cardiopulmonary Bypass

Atrial septal aneurysm is an uncommon cardiac anomaly that is usually asymptomatic or occasionally associated with cardioembolic events. We present the unusual impeding effect of an atrial septal aneurysm on venous drainage during cardiopulmonary bypass in a 70-year-old man who underwent aortic valve replacement and coronary artery bypass graft surgery.