cardiovascular disorders
Atrial Fibrillation
Classification of Atrial Fibrillation
Paroxysmal atrial fibrillationis atrial fibrillation that lasts<1 week having converted spontaneously or by an intervention to normal sinus rhythm. Episodes may recur. Persistent atrial fibrillationis continuous atrial fibrillation that lasts>1 week. Long-standing persistent atrial fibrillationlasts > 1 year, but there is still the possibility of restoring sinus rhythm. Permanent atrial fibrillationcannot be converted to sinus rhythm (the term also includes patients for whom a decision has been made not to attempt conversion to sinus rhythm). The longer atrial fibrillation is present, the less likely is spontaneous conversion and the more difficult is cardioversion because of atrial remodeling (rapid atrial rate-induced changes in atrial electrophysiology that are dominated by a decrease in atrial refractoriness and may also include increase in spatial dispersion of atrial refractoriness, slowed atrial conduction velocity, or both). 