Epidemiology and therapy of atrial fibrillation
Capucci, A.; Aschieri, D.; Villani, G.Q.
Annali Italiani di Medicina Interna Organo Ufficiale Della Societa Italiana di Medicina Interna 11(Suppl 2): 5s
1996
ISSN/ISBN: 0393-9340 PMID: 9004821 Document Number: 464680
Atrial fibrillation (AF) is the most common supraventricular arrhythmia in the Western world and its prevalence increases with age. The objectives of the pharmacologic treatment of AF are mainly three: to restore sinus rhythm, to maintain sinus rhythm, and to control ventricular rate during AF. Class 1C antiarrhythmic drugs (propafenone, flecainide) have been demonstrated to be the most effective drugs in restoring sinus rhythm with low risk/benefit and cost/benefit ratios and percentage efficacy rate between 50% and 60%. The long-term efficacy of antiarrhythmic therapy for preventing AF recurrences is far from ideal. Different studies have reported unsatisfactory results with class 1C, class III (sotalol) and class 1A (quinidine, diisopyramide) antiarrhythmic drugs. Calcium channel blockers (diltiazem, verapamil) alone or in combination with digitalis are the drugs of choice in ventricular rate control. New pharmacologic approaches may be hypothesized based on the experimental evidence of 5-hydroxy-triptamine receptors in human atria. Non pharmacologic attempts introduced for AF therapy include: pacemaker implantation, catheter ablation, surgical procedures, internal defibrillation. Atrial fibrillation in patients with tachycardia-bradycardia syndrome is an important indication for permanent pacing. With the advent of dual chamber stimulation it has become apparent that atrioventricular sequential pacing may be superior to VVI pacing in patients with sick sinus syndrome where it may prevent the development of chronic AF. Catheter ablation of atrioventricular node is an accepted approach in patients with drug refractory AF, in patients with sick sinus syndrome where pacemaker therapy failed to prevent paroxysmal AF, or in patients with ICD in order to avoid inappropriate DC-shock. Surgical interventions for AF aim at maintaining sinus rhythm by confining the arrhythmia within the left atrium (left atrial isolation technique) or to both left and right atrium (corridor technique). Another procedure (maze) consists of multiple incisions in the right and left atrium. Recently internal low energy cardioversion has been demonstrated to be effective in treating AF in animal models, and initial clinical studies have shown it can be useful in cardioverting chronic AF in humans as well, suggesting the potential usefulness of an implantable cardioversion device in clinical practice.