In AF, the normal electrical impulses that are generated by the sinoatrial node are overwhelmed by disorganized electrical impulses that originate in the atria and pulmonary veins, leading to conduction of irregular impulses to the ventricles that generate the heartbeat. The result is an irregular heartbeat, which may occur in episodes lasting from minutes to weeks, or it could occur all the time for years.
Atrial fibrillation is often asymptomatic and is not in itself generally life-threatening, but it may result in palpitations, fainting, chest pain, or congestive heart failure. People with Atrial fibrillation usually have a significantly increased risk of stroke.
The American College of Cardiology, American Heart Association,and the European Society of Cardiology recommend the following classification system
All atrial fibrillation patients are initially in the category called first detected AF. If a first detected episode self-terminates in less than 7 days and then another episode begins later on, it is paroxysmal AF. In most cases of paroxysmal AF the episodes will self-terminate in less than 24 hours.If the episode lasts for more than 7 days, it is unlikely to self-terminate and it is called persistent AF.If cardioversion is unsuccessful or the episode is ongoing for a long time (e.g. a year or more), the patient's AF is called permanent.