I think what you are getting at is whether or not having paroxysmal (or transient) atrial fibrillation puts you at just as high as risk of stroke as someone who
has permanent atrial fibrillation. The answer to that would be, yes. In fact, paroxysmal atrial fibrillation, in experience, is somewhat more dangerous because when the heart goes back into a regular rhythm it is more prone to actively pump out clots that have formed during atrial fibrillation, and because the patient is less aggressive or less knowledgeable about the potential risks. The bottom line is that atrial fibrillation, even if only occasional, is a very strong risk factor for stroke, and the strokes that occur due to atrial fibrillation tend to be severe. In fact, the most severe strokes that I typically see are caused by atrial fibrillation. Therefore, if you have this condition, even transiently, I would have a serious discussion with your doctor about starting on anticoagulation therapy - typically either with warfarin (Coumadin) or dabigatran (Pradaxa).