How Is an Intracardiac Shunt Diagnosed?
Patent foramen ovales (PFO) and atrial septal defects (ASD) are often diagnosed by an ultrasound of the heart (echocardiogram), often with a saline bubble test.
An echocardiogram allows for the visualization of the hole, determination of the direction of the shunt, and estimation of the amount of shunt.
Other imaging tests include: transesophageal echo (TEE), cardiac CT and cardiac MRI (CMR). These may be done if an echocardiogram is inconclusive or if supportive information is required.
Cardiac catheterization (and to a lesser extent, CMR) can be performed to give a more accurate estimation of the degree of shunt when the decision to treat is unclear.