Biplane transesophageal echocardiography in the diagnosis of patent foramen ovale.

Patent foramen ovale is associated with unexplained systemic embolic events or persistent hypoxemia. The diagnosis of a patient foramen ovale is based on the existence of an interatrial right-to-left shunt. Biplane transesophageal echocardiography with its increased ability to provide accurate anatomic detail may allow the visualization of the actual opening of the patent foramen ovale. In 19 patients with transesophageal positive contrast studies, we assessed the value of the vertical versus the horizontal plane in the diagnosis of a patent foramen ovale. The patent foramen ovale opening could be seen and sized in the vertical plane in 10 studies (53%). In none of these 10 cases was the opening seen also in the horizontal plane. We conclude that in a significant number of cases, biplane transesophageal echocardiography adds morphological detail to the diagnosis of patent foramen ovale. The ability to size the actual opening may have therapeutic implications.