Patent foramen ovale (PFO) has been linked to several clinical syndromes including cryptogenic stroke in the young , decompression sickness in divers , and migraine with aura . PFO is common, occurring in 20.2% to 34.4% of autopsies depending on age .

The management of PFO remains controversial, and although not yet approved by the U.S. Food and Drug Administration, transcatheter approach to PFO closure continues to develop. Potential complications include device embolization, thrombus formation, atrial arrhythmias, residual shunting, and device erosion or perforation . A careful assessment of the anatomy of the atrial septum is necessary to reduce such risks. This article focuses on the role of echocardiography in the evaluation of PFO for transcatheter closure. It provides an easy to understand account of the development and functional anatomy of the atrial septum and provides the reader with a systematic and comprehensive approach to transesophageal echocardiographic (TEE) study in such a patient . The salient information required for planning the device and equipment needed for the closure procedure are discussed.