Patent Foramen Ovale Workup

Updated: Dec 17, 2017
  • Author: Sandy N Shah, DO, MBA, FACC, FACP, FACOI; Chief Editor: Yasmine S Ali, MD, MSCI, FACC, FACP  more...
  • Print

Approach Considerations

No specific laboratory tests are necessary to diagnose patent foramen ovale (PFO), and no specific electrocardiographic findings are noted in affected patients


Imaging Studies


In some instances, patent foramen ovale (PFO) is detectable with color flow Doppler imaging. A small "flame" of color signal may be seen in the middle region of the atrial septum.

Contrast echocardiography is usually required to detect small PFO. After obtaining optimal visualization of the atrial septum on transthoracic or transesophageal echocardiography, a bolus of agitated saline is injected into an antecubital vein. Subsequently, microbubbles appear in the right atrium. The study is positive for PFO if the microbubbles appear in the left atrium within 3 cardiac cycles of their appearance in the right atrium. Valsalva maneuver increases right atrial pressure and facilitates right-to-left shunting.

Two-dimensional transesophageal echocardiography (2D TEE) with contrast provides superior visualization of the atrial septum and therefore is preferred to transthoracic contrast echocardiography for detecting PFO. When clinically indicated, 2D TEE with contrast is strongly recommended for patients whose findings on transthoracic echocardiography are negative.

A 3-dimensional transesophageal echocardiography (3D TEE) provides direct visualization of the entire PFO anatomy and surrounding structures. It allows more accurate diagnosis of PFO by direct visualization of the bubbles crossing fossa ovalis. [6]

A small study evaluated transmitral Doppler (TMD) echocardiography with agitated saline contrast in 44 patients. The sensitivity and specificity of TMD were 100% and 96% when compared with TEE. Greater than 10 bubbles on a single beat of resting-contrast TMD correlated with a maximum resting TEE PFO opening diameter greater than 2 mm with 78% sensitivity and 100% specificity. In current practice, role of TMD is uncertain due to limited experience. [7]

Transcranial Doppler (TCD) is an alternative to TEE. TCD is a noninvasive test that can be easily performed at the bedside. However, it can only detect right-to-left shunt, not the location of the shunt. [8]

TCD and TEE are comparable for detection of right-to-left shunts. However, TEE is a better test because it provides anatomic information about the site and size of shunt. It also helps to detect presence of other causes of stroke such as intracardiac mass, atrial septal aneurysm, infective endocarditis, and aortic atherosclerosis. [15]

In an evaluation of 2680 patients with cryptogenic stroke, researchers found that strokes with certain radiologic characteristics were more likely to be associated with PFO. In the study, the investigators determined that strokes that were small, deep, or not apparent on radiologic imaging were less likely to be associated with PFO than were large, superficial, or radiologically apparent strokes. An association was also found between PFO and strokes that had no relation to previous radiologic infarcts. [16]