Unlike flecainide and propafenone, it can be used in patients with structural heart disease or ischemic heart disease. One study randomized patients with reentrant SVT (AVNRT or AVRT) or other atrial tachyarrhythmias (eg, AF, atrial flutter, AT) to sotalol at a dose of 80 mg or 160 mg twice daily or placebo and found significant reductions in recurrence risk, including for patients with reentrant SVT, with no proarrhythmic adverse effects.114 Because of the potential for proarrhythmia, sotalol should be reserved for patients who are not candidates for catheter ablation and for whom beta blockers, diltiazem, or verapamil are ineffective or cannot be prescribed. IIb B-R Dofetilide may be reasonable for ongoing management in patients with symptomatic SVT who are not candidates for, or prefer not to undergo, catheter ablation and in whom beta blockers, diltiazem, flecainide, propafenone, or verapamil are ineffective or See Online Data Supplement 2. Dofetilide is a class III antiarrhythmic agent that, unlike sotalol, does not have beta-blocker properties. It may be reasonable in patients with structural heart disease or ischemic heart disease. In a trial of 122 patients randomized to dofetilide, propafenone, or placebo, the probability of remaining free of SVT after 6 months of treatment was 50% for dofetilide, 54% for propafenone, and 6% for placebo, with P<0.001 for either dofetilide or propafenone compared with placebo.107 Because of the potential for proarrhythmia, dofetilide should be reserved for patients who are not candidates for catheter ablation and for whom beta blockers, diltiazem, flecainide, verapamil, or propafenone are ineffective or cannot be prescribed. 