title: Chronic atrial fibrillation: spontaneous conversion to sinus rhythm. Improvement in arrythmia may actually represent a worsening of the conduction system.
mesh_terms: D001281:Atrial Fibrillation; D002908:Chronic Disease; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008875:Middle Aged