It was in 1984 this paper came from mayo clinic proceedings .
Hagen PT, Scholz DG, Edwards WD. Incidence and size of patent foramen ovale during the first 10 decades of life: an autopsy study of 965 normal hearts. Mayo Clin Proc. 1984;59:17-20.
When interventional cardiology was not even in infancy . Now it remains the only data base of nearly 100o hearts studied after autopsy .
After reading the article I got few surprises
Mayo clinic continues to be pioneers in providing vital research about PFO
Following is another excellent review article on PFO and stroke