Current management of symptomatic atrial fibrillation

Abstract

Atrial fibrillation (AF) is the most commonly encountered sustained arrhythmia. Heart rate control, reduction of symptoms, and prevention of embolism are major goals of treatment. Whether the strategy of cardioversion with subsequent maintenance of sinus rhythm has an advantage over heart rate control is under active investigation. Digoxin, non-dihydropyridine calcium channel antagonists, beta-adrenoceptor antagonists (beta-blockers), and amiodarone are the pharmacologic agents most commonly used to achieve rate control. In patients with drug-resistant AF, atrioventricular nodal ablation (or modification) with implantation of a permanent pacemaker is an alternative therapy. Conversion to sinus rhythm can best be achieved by electrical cardioversion. In selected patients, pharmacologic cardioversion can also be attempted. The use of antiarrhythmic drugs for the maintenance of sinus rhythm depends on several factors: (i) the nature of the arrhythmia (first attack, paroxysmal AF with frequent attacks, paroxysmal AF with infrequent attacks, or persistent AF); (ii) the associated symptoms; (iii) and the risk of severe adverse effects associated with the chosen drug. If the administration of an antiarrhythmic drug is appropriate, the choice of the drug must be tailored to the specific characteristics of the given patient. In lone AF, class Ic antiarrhythmic drugs are the best tolerated. These agents should be combined with a calcium channel antagonist or a beta-blocker to prevent rapid ventricular response in the case of conversion of AF to atrial flutter. In this situation, catheter ablation of atrial flutter at the isthmus (hybrid therapy) should be performed. All class I antiarrhythmic agents should be avoided in patients with structural heart disease. Alternative approaches that may be used if sinus rhythm cannot be maintained with drug therapy include: (i) the ablation of arrhythmogenic pulmonary veins; (ii) the implantation of an atrial defibrillator; (iii) the use of specific pacing sites; (iv) or pacing modes. Whether these approaches will reach clinical relevance merits further investigation. Intraoperative catheter ablation or surgical ablation (maze procedure) seems a promising approach for curing AF in patients undergoing cardiac surgery. Among all of the available treatment options, the most consistent proof of efficacy in reducing mortality and morbidity from AF exists for antithrombotic treatment.