I have written a huge amount about migraine in the past. I also had become aware of the conntection to the heart problem. Having said this, one of my friends has just been fitted with a pacemaker after 68 years of being quite fit. He didn't know about the hole until in his 60s...and then it was only found by chance. The theory is that the heart releases a homone that triggers the problem. He certainly suffered bad migraine most of his life, but it was always much worse when life had handed out some serious blows.
Again, I say my broad outline advise is -- one or perhaps two attacks at a time of great stress (CAUSING CHRONIC WORRY) leaves the patient with a chance that it will never happen again. More than that, and you can be classed as a sufferer and should never hold any form of pilot's licence. However cruel this may seem, the concept of never knowning when you are going to suddenly not be able to see is an obvious bar to flying. The following headache and sickness can be totally disabling.
Be aware that under the old rules, even one attack barred you from even a PPL.