Can having a patent foramen ovale cause permanent damage to the heart?

No. A patent foramen oval is present in up to 1/3 of the population. Their presence does not cause damage to the heart.
It is permanent. Damage. A patent foramen ovale is permanent damage to the heart due to developmental issues. It also makes it possible for a person to have an unusual complication of embolism, namely, paradoxical embolism; i.e., venous embolus can cross over to the arterial side.

Related Questions

My son (age 15) just had a physical and a heart mumur - he had a electrocardiogram and found patent foramen ovale - should he have surgery to close?

Depends. A patent formen ovale is usually asymptomatic and does not require treatment, however, the issue needs to be assessed by a cardiologist to ensure that there is no other cardiac anomaly. See this site for more information. Read more...
Not necessarily. Even if he is extremely healthy, go see a pediatric cardiologist. They will do a 2d echocardiogram which will answer your questions. Read more...