Flecainide may play an important role in the treatment of ventricular arrhythmias because of its convenient dosing regimen and high rate of efficacy in controlling ventricular ectopic activity. In stable patients with normal or mildly reduced left ventricular function, flecainide has proved to be promising. In those patients with severe left ventricular dysfunction, lethal arrhythmias, and preexisting conduction system disease, caution must be exercised.