LAUSR

Recent prospective controlled studies have demonstrated that transcatheter closure of a patent foramen ovale (PFO) reduces recurrent stroke risk in select patients, especially in patients younger than 60 years with PFO and embolic-appearing infarct and where no other mechanism of stroke was identified. Detection of PFO depends on the intensity of the Valsalva maneuver, and not all PFOs can be diagnosed using transesophageal echocardiography. Transthoracic contrast echocardiography using abdominal compression during the Valsalva maneuver is an easy method that can increase the detection sensitivity of PFO shunt. PFO with two or more of the following factors is most likely considered a "high-risk PFO" and as such, has a significantly higher probability of cryptogenic stroke: (1) a long-tunnel PFO (≥10 mm in length), (2) atrial septal aneurysm and/or hypermobile interatrial septum, (3) prominent Eustachian valve or Chiari's network, (4) large right-to-left shunt at rest and during the Valsalva maneuver, and (5) low-angle PFO. In order to establish the benefit of catheter-based PFO closure as a safe and effective treatment in clinical practice, the degree of accuracy of PFO diagnosis and its long-term safety need to be confirmed.