Grump, I can say that. On July 3, 2010 I had a brief TIA which put me firmly within the medical system. Many test later (MRIs, CAT scans, echo this, echo that and the treadmill) a PFO was discovered, about 8mm. I heard the term idiopathic a lot- medical speak for "your guess is as good as ours". I wasn't yet 60 years old and was in excellent health and physical condition. Apparently I either suffered blunt force trauma from one of my llamas or performed the Valsalva maneuver once too often while cutting and carrying firewood. My cardiologist made a video of the PFO in action while I was doing an extreme stress test on the treadmill. Mine does not open until I am at the upper end of my exertion. He rates the PFOs on a scale of 1-5, a 5 gets you into surgery asap. I was rated a 2-3.

My two best choices for dealing with the PFO are to either have a tyvek closure device inserted in my heart or scale back my rough and tumble ways, the cardiologist also suggested I not SCUBA deeper than 50' or climb higher than 7500'. I chose to not have a device put in my heart. I don't dive, but I have been above 7500' several time and I still do two week trips and work up a healthy sweat. As much as possible I avoid trauma to my body and Valsalva. It helps that llamas carry most of my gear.

Good luck with your condition. I might still have links to some of what I learned if you are interested.