I read the 70 odd posts with interest.
It was mostly a good debate.
This is how my heart surgeon explained it to me.
The aorta has a sac - its like a little bag hanging down somewhere just after the valve from the heart. When we are in sinus (normal) rythym with every heart beat this valve fills and empties with blood.
When we are in AF the sac doesn't completely empty - thats when clots can form - they sit in the bottom of the sac and when we go back to normal rythym the sac empties and we are playing russian roulete .
It happened to me , I was was lucky the clot landed in my arm.
At the time I was on aspirin.
Thats why Im now on warfarin.