When and how to diagnose patent foramen ovale.

This article presents information related to the diagnosis of patent foramen ovale (PFO). PFO is a common finding in the healthy population, with a prevalence of 27% in one necropsy study of 965 normal hearts from patients with no history of cardioembolic events. The larger size of a PFO and greater number of microbubbles passing through a shunt during echocardiography has also been associated with an increased incidence of cerebrovascular events. Transoesophageal echocardiography (TOE) is superior to transthoracic echocardiography for the diagnosis of a PFO and delineation of its morphologic details. Hence, TOE is regarded as the imaging procedure of choice in adult patients with suspected paradoxical embolism.