Abstract
Atrial septal defect closure is now routinely performed using a percutaneous approach under echocardiographic guidance. Since some echocardiographic features play an important role in the assessment of the defect and safety of the procedure, the salient features of the anatomical variations seen in adults undergoing transcatheter device closure should be well known to prevent inadvertent adverse effect or complications. It has been reported that the valve of the inferior vena cava, Eustachian valve, could be mistaken as the atrial septum thus ending in a wrong diagnosis and causing inadvertent surgical or percutaneous closure of an Eustachian valve to interatrial septum. We present a concise article that brings out a practical issue encountered during device closure of atrial septal defects.