The sudden onset of atrial fibrillation (AF) is often associated with rapid irregular palpitations, chest pain,
shortness of breath and considerable anxiety. If a patient presents shortly after the onset of the arrhythmia the physician
may adopt initially an expectant “wait and see” policy, perhaps with the help of mild sedation and drug therapy to reduce
the ventricular rate. If the arrhythmia does not terminate spontaneously and has been present for less than 24-48 hours restoration
of sinus rhythm by cardioversion should be considered. This manuscript reviews the option of electrical cardioversion
versus pharmacologic and the data for, the role of, and the status of vernakalant with respect to the latter.