What are the symptoms of patent foramen ovale?

Mostly asymptomatic: A patent foramen ovale is a common developmental anomaly and is usually asymptomatic, if there are no other cardiac abnormalities. It does predispose the person to an uncommon event called paradoxical embolism where a venous embolus crosses over to the arterial side.

Usually none: Most pfo's are asymptomatic. In rare instances of clot formation, it can cross from venous to arterial side and cause stroke.