Much of the data pertaining to use of amiodarone in management of atrial arrhythmias has been derived from use in patients with AF.10 Few data are available for patients with atrial flutter. Amiodarone has significant toxicities, so it is used only when other treatments are contraindicated or ineffective. Nevertheless, administration is reasonable, particularly in patients with heart failure or significant underlying heart disease.376 Dofetilide may be more effective than many other drugs but must be started in an inpatient setting.346,377 The dose is adjusted on the basis of renal function, with close monitoring of the Q-T interval and subsequent monitoring for altered renal function. Sotalol, a class III antiarrhythmic, is generally well tolerated but is associated with typical beta blocker side effects, such as fatigue and The major potential cardiac toxicity for both drugs is torsades de pointes. IIa B-NR Catheter ablation is reasonable in patients with CTI-dependent atrial flutter that occurs as the result of flecainide, propafenone, or amiodarone used for treatment of AF.317,379 381 See Online Data and 17. Some patients with AF treated with propafenone, flecainide, or amiodarone will develop atrial flutter. In this circumstance, if flutter becomes the dominant arrhythmia, ablation of the CTI and continued use of the antiarrhythmic drug can decrease the incidence of atrial flutter and facilitate the pharmacological management of AF.379,380 IIa C-LD Catheter ablation of the CTI is reasonable in patients undergoing catheter ablation of AF who also have a history of documented clinical or induced CTI-dependent atrial flutter.381,382 See Online Data and 17. 