How long can i live with a patent foramen ovale if it was never corrected?

A normal duration: The presence of a patent foramen ovale has not been shown to affect life expectancy in the general population.

Depends: If you are asymptomatic, forever. That is a normal life span.

Size: Pfos are very common, up to 20% of the population and most are very small. However, if the opening is large with a significant amount of flow across, it can eventually lead to cardiac issues suck as heart failure so i would argue that it depends on size but most people do just fine.