Atrial fibrillation: A review of mechanism, etiology, and therapy

Abstract

Summary:The prevalence of elderly individuals in the populations of developed countries is increasing rapidly, and atrial tibrillation (AF) is quite common in these elderly patients: currently, 11 % of the U.S. population is between the ages of 65 and 85 years; 70% of people with AF are between the ages of 65 and 8.5 years. AF causes symptoms secondary to hemodynamic derangements that are the result of increased ventricular response and loss of atrial booster function. AF can lead to reversible impairment of left ventricular function, cardiac chamber dilatation, clinical heart failure, and thromboembolic events. AF requires treatment in order to prevent these potential complications. Type la, Ic, and 111 antiarrhythmics are capable of converting AF to normal sinus rhythm (NSR). Amiodarone has the greatest efficacy and safety for converting AF and maintaining NSR while digoxin and verapamil are ineffective in restoring NSR. Quinidine, flecainide, disopyramide, and sotalol have also been shown to maintain NSR after conversion of AE Proarrhythmia is a definite concern with the latter four agents. Alternative therapy for AFindudes anticoagulation with warfarin or aspirin for the prevention of thromboembolic events, and a variety of agents to control the ventricularresponse. All medications used to treat AF carry significant risks in the elderly, whether from proarrhythmia, overdosing because of compliance errors, or hemorrhage secondary to anticoagulation. Treatment of AF must be based on a careful risk-benefit evaluation. The physician must know the capability of the particular patient as well as

Cost-effectiveness of Therapies for Patients With Nonvalvular Atrial Fibrillation

“…25 Amiodarone is highly effective in maintaining sinus rhythm; initial fears about toxicity have been tempered because that toxicity is in large part a function of dosage, and atrial fibrillation is being treated with a relatively low dosage. 21 …”

“…[21][22][23] In this study, we considered a variety of strategies for the treatment of atrial fibrillation but focus on 3 antiarrhythmic drugs, reflecting their common use in the last decade. 21,22,24 Quinidine is still widely used, although possibly decreasing in popularity. 25 Sotalol hydrochloride is generally well tolerated and is widely used for treatment of atrial fibrillation in Europe and Canada.…”

Atrial fibrillation: Now one of the most common causes for hospitalization

“…From 1987 to 1989, the Framingham population demonstrated a 7.8% prevalence of AF in men aged 65 to 74; the corresponding prevalence in men aged 75 to 84 was 11.7%. Thus, the prevalence of AF is increasing markedly in industrialized nations secondary to growth in the population of elderly individuals in these societies [1][2][3]. However, even the age-adjusted prevalence of AF has increased recently, suggesting that age alone does not account for all of the increased frequency with which physicians are encountering patients with this arrhythmia [3].…”

“…For instance, therapy with digoxin does not prevent recurrent episodes of AF although β-blocker administration can accomplish this goal [2,5]. Idiopathic or "lone" AF is not as benign an entity as once thought; Jouven et al [6] observed a fourfold increase in cardiovascular mortality and a twofold increase in all cause mortality for middleaged Frenchmen with lone AF.…”

“…In the United States, AF affects approximately 2.2 million adults with a median age of 75 years. Amazing but true is the observation that nearly 10% of individuals over the age of 80 manifest this arrhythmia [1,2]. Clearly, the incidence and prevalence of AF increase substantially with age.…”