Paroxysmal & Refractory Atrial Fibrillation

A. Recurrent Paroxysmal Atrial Fibrillation
It is now well established that patients with recurrent paroxysmal atrial fibrillation are at similar stroke risk as those who are in atrial fibrillation chronically. While these episodes may be apparent to the patient, many are not recognized and may be totally asymptomatic. Thus, ambulatory electrocardiographic monitoring or event recorders are indicated in those in whom paroxysmal atrial fibrillation is suspected. Antiarrhythmic agents are usually not successful in preventing paroxysmal atrial fibrillation episodes. However, immediate self-administered treatment with an antiarrhythmic agent (experience is perhaps greatest with propafenone, 300 mg orally, repeated once after 2-3 hours if necessary) may interrupt symptomatic episodes, and chronic use of a beta-blocker or rate-slowing calcium channel blocker may reduce the severity of symptoms. In any case, chronic anticoagulation is indicated except in those who are under 60-65 years of age and have no additional stroke risk factors.

B. Refractory Atrial Fibrillation
Because of trial results indicating that important adverse clinical outcomes (death, stroke, hemorrhage, heart failure) are no more common with rate control than rhythm control, atrial fibrillation should generally be considered refractory if it causes persistent symptoms or limits activity.

This is much more likely in younger individuals and those who are very active or engage in strenuous exercise. Even in such individuals, two-drug or three-drug combinations of a beta-blocker, rate-slowing calcium blocker, and digoxin usually can prevent excessive ventricular rates, though in some cases they are associated with excessive bradycardia during sedentary periods. If rapid ventricular rates persist, amiodarone may be substituted for or added to these agents.

If no drug works, radiofrequency AV node ablation and permanent pacing ensure rate control and may facilitate a more physiologic rate response to activity. There is growing experience with focal ablation of foci in the pulmonary veins that initiate atrial fibrillation, following which sinus rhythm may be restored or maintained. A surgical approach called the Maze procedure can also be used to eliminate the multiple reentry circuits that cause atrial fibrillation, and implantable atrial defibrillators can be used to convert paroxysmal episodes. The role of these latter procedures is limited, however.

Preferences:
Albers GW et al: Antithrombotic therapy in atrial fibrillation. Chest 2001;119:194S.

Chugh SS et al: Epidemiology and natural history of atrial fibrillation: clinical implications. J Am Coll Cardiol 2001;37:371.

Falk RH: Atrial fibrillation. N Engl J Med 2001;344:1067.

Fuster V et al: ACC/AHA/ESC guidelines for the management of patients with atrial fibrillation: executive summary. A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines and Policy Conferences (Committee to Develop Guidelines for the Management of Patients with Atrial Fibrillation): developed in Collaboration with the North American Society of Pacing and Electrophysiology. J Am Coll Cardiol 2001;38:1231.

Klein AL et al: Use of transesophageal echocardiography to guide cardioversion in patients with atrial fibrillation. N Engl J Med 2001;344:1411.

Madrid AH et al: Use of irbesartan to maintain sinus rhythm in patients with long-lasting persistent atrial fibrillation: a prospective and randomized study. Circulation 2002;106: 331.

Maisel WH et al: Atrial fibrillation after cardiac surgery. Ann Intern Med 2001;135:1061.

Ng FS et al: Catheter ablation of atrial fibrillation. Clin Cardiol 2002;25:384.

Pappone C et al: Atrial electroanatomic remodeling after circumferential radiofrequency pulmonary vein ablation. Circulation 2001;104:2539.

Peters NS et al: Atrial fibrillation: strategies to control, combat, and cure. Lancet 2002;359:593.

Wyse DG et al: A comparison of rate control and rhythm control in patients with atrial fibrillation. N Engl J Med 2002;347: 1825.

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Revision date: July 3, 2011
Last revised: by Dave R. Roger, M.D.