NONPHARMACOLOGIC STRATEGIES FOR TREATING ATRIAL-FIBRILLATION

Nonpharmacologic tools to treat atrial fibrillation (AF) are direct cu rrent cardioversion, radiofrequency (RF) current catheter ablation, an tiarrhythmic surgery, pacing, and atrial defibrillation. In patients w ith sustained AF, when no cause can be found for AF or when the associ ated disease is mild, an attempt should be made to restore sinus rhyth m. Electrical cardioversion by synchronized direct current shock can b e attempted when drugs have failed and is the first choice in acutely ill patients. Virtually all patients should be anticoagulated. Tempora ry pacing should be available in patients with evidence of previous br adycardia. Although efficacy may be improved in patients pretreated wi th antiarrhythmic drugs, there is a considerable risk of adverse event s. In AF and sinus node dysfunction, both pacing and antiarrhythmic dr ugs may be necessary. Pacing should be atrial or dual chamber, since v entricular pacing provokes AF. Failure to control the ventricular rate in AF can be treated by RF: atrioventricular (AV) node ablation, abla tion of accessory pathways in preexcitation syndrome with AF, modulati on of AV node, or ablation of AF. Antiarrhythmic surgery is a major pr ocedure and may be the therapy of last resort in AF: the so-called cor ridor procedure isolates the fibrillating atria from a strip of tissue connecting the sinus and AV nodes. The maze procedure attempts to abo lish AF by channeling the atrial activation between a series of incisi ons. In patients with chronic AF, internal cardioversion should be att empted if conventional trans-thoracic electrical cardioversion is inef fective. Several studies demonstrated the feasibility and efficacy of internal atrial defibrillation in selected patients with recent onset, as well as with chronic, AF. An implantable atrial defibrillator-as a stand-alone device or as part of a whole heart cardioverter-might be an option in the future. Nonpharmacologic tools play only a minor role in the management of paroxysmal and chronic AF. If symptoms persist d espite pharmacologic therapy and other causes of persisting symptoms a re excluded, consideration should be given to cardiac pacing, RF cathe ter treatment, or surgery. In some eases nonpharmacologic therapy of t he AV node must be followed by implantation of a permanent pacemaker ( due to complete AV block) and anticoagulation (due to persistence of u nderlying AF).