PFO and Exercise

[runningbarbie]

Four the past 4 years, I have been experiencing pain/tingling in my left hand.  After having it for a few days, then would come, blurred vision,stumbling,dizziness, and fatigue.  There was a slow build up to it lasting 2-8 weeks.  All evoked potentials and MRI's came back normal.  Blood work came back clear except for a small elevation in my HCT and HGB.  I figured this was from the amount of running I do.  
A Transcranial Doppler was done which showed a grade IV right to left PFO.  I have started taking Aggrenox and it is a wait and see process.
I have been a avid runner for the last 10 years and actually made my self run when I was having my episodes.  It is the one thing that actually made me feel a little better. But sometimes if I ran far, it would kick up my symptoms. When I was not feeling well, it would be just 30 minutes.  When I was doing good, up to 90 minutes.  4 years ago I was doing marathons and ulta marathons.
So my question is, why did things change in the last four years?  Is it ok to continue to run?  Why would my running stir up my symptoms?  Could it be hypoxia?
Side note:  Have had migraine with aura once a year that has only happen during running.

[Cleveland Clinic]

You need an echocardiogram to verify the presence of an intracardiac shunt, as there are other possibilities for shunts elsewhere in the circulation. If you have a PFO, and indeed have right to left shunt flow, then the question is what is the magnitude of the shunt. This can only be answered via a right heart catheterization,l wherein one can also measure sequential oxygen saturations and actually find if there are other sites for shunting, and the severity of the pulmonary pressures.
Irrespective of the magnitude of the PFO flow ( that is that there is no ASD present) with your symptoms of TIAs you meet qualifications for closure, possibly via an endovascular device, of the PFO. This will substantially reduce the future risk of stroke an dprobably reduce any hypoxia.

[momtofourboys]

I have a PFO, and so does my 4 year old. I am not sure how big mine is, however his is small and he has many other things. I can't answer your question, but I want to make you aware of something that I was told and not sure if you have been told.(I was not told by my sons's cardiologist ) I was actually told that I had a PFO by the anastesiologist(spelled it wrong I think) that was doing my surgery when he went over my history. I had no idea. he told me that if I were to EVER have an IV to make sure that they put a filter on the line to help keep the air bubbles down in the line. I aske my sons doctor about this and he said yes. so please make sure you have a filter on any sort of IV line like when surgery  or something like that
sorry I can't help you.
Michelle

[runningbarbie]

Hmm.  That is weird.  Dont know why that would be being when they do a transcranial doppler, they put bubbles in your line to see if they go straight to the brain.  Interesting.  I will have to look it up.