Chiari network with interatrial septum defect and aneurysm

Chiari network is a embryogenic remmant of sinus venosus. This network tissue regresses during later growth leaving remnants in the right atrium. Chiari network does not regress completely and remnants remain in the right atrium in 2% of population. Remnants of Chiari-network  are frequently confused with thrombus and vegetation on echocardiographic examinations. Chiari network is usually associated with interatrial septal defect and interatrial septal aneurysm. Chiari network can cause tricuspid valve regurgitation, atrial fibrillation, paradoxical embolism and bacterial embolism. We have performed surgery for Chiari network which was caused transient emboli and transient atrial fibrilllation.