What Causes Atrial Fibrillation?

Where does atrial fibrillation come from and what causes it?

We know that the erratic electrical impulses that cause atrial fibrillation often originate in the pulmonary veins, at

least in most paroxysmal (intermittent) atrial fibrillation, and that the impulses that cause persistent and longstanding

persistent atrial fibrillation are believed to come from other areas as well, but what actually causes afib? Though

researchers are investigating the cause of atrial fibrillation, as of now it is largely unknown except that some recent

studies have shown a genetic component as afib often runs in families.