Clinical challenge. II. Management of recent onset atrial fibrillation. PAFIT-2 Investigators

Atrial fibrillation is a very common arrhythmia in patients with structural heart disease, but it also occurs in patients without underlying heart disease. Acute therapy for paroxysmal atrial fibrillation is very dependent on the clinical condition of the patient. Direct current cardioversion is usually the first choice whenever the arrhythmia precipitates heart failure or severe angina, while more stable patients are normally treated with drugs. Most episodes of atrial fibrillation eventually convert to sinus rhythm even in the absence of treatment. Antiarrhythmic drugs can be used to control the ventricular response or to restore sinus rhythm, and several have been tested to assess their ability to convert recent onset atrial fibrillation. The success rate has varied, but generally flecainide and propafenone appear the most effective. Digitalis and calcium channel blockers do not increase the likelihood of reversion but they reduce ventricular rate. Amiodarone has been tested as a possible alternative to flecainide and propafenone. The pros and the cons of these and other drugs in the setting of paroxysmal atrial fibrillation will be discussed. In particular, special emphasis will be given to the differences in the design and in patient selection of the trials that tested antiarrhythmic drugs in paroxysmal atrial fibrillation.