There is no known cause, and there are usually no symptoms associated with PFO. Treatment is not necessary in most PFO cases.However, the larger the hole, the more likely symptoms are to occur. Patent foramen ovale (PFO). Similar to an ASD, a patent foramen ovale is a type of hole in the septal tissue that separates the upper chambers of the heart. Diagnosis: There are usually no symptoms associated with PFO but an imaging test called an echocardiogram can be used to diagnose a PFO. With PFO, instead of an open hole, there is a flap-like structure that opens when there is pressure in the chest, such as coughing or sneezing. A patent foramen ovale is a small, flaplike opening in the wall between the upper chambers of the heart. Northwestern Medicine Neuroscience programs provide treatment for a full range of potential neurological concerns, including patent foramen ovale. Most people will not have any signs or symptoms directly from PFO at all.