MANAGEMENT OF ATRIAL-FIBRILLATION IN ADULTS - PREVENTION OF THROMBOEMBOLISM AND SYMPTOMATIC TREATMENT

Because of its prevalence in the population and its associated underly ing diseases and morbidity, atrial fibrillation (AF) is an important a nd costly health problem. Advancing age, diabetes, heart failure, valv ular disease, hypertension, and myocardial infarction predict the occu rrence of AF within a population. The management of AF is complex and involves prevention of thromboembolic complications and treatment of a rrhythmia-related symptoms. Stroke occurs in 4.5% of untreated patient s with AF per year. Independent risk factors for stroke in nonrheumati c patients with AF are advanced age; a history of prior embolism, hype rtension, or diabetes; and echocardiographic findings of left atrial e nlargement and left ventricular dysfunction. Warfarin decreases stroke by two-thirds and death by one-third; aspirin is only about half as e ffective overall and is insufficient therapy for those with risk facto rs for stroke. Options for thromboembolic prophylaxis are use of warfa rin for all in whom it is safe or, alternatively, warfarin for those w ith risk factors and aspirin for those without risk factors. One-half of the patients with AF are 75 years of age or older. The uniform appl icability and relative safety of warfarin therapy in this age-group ar e controversial. Specific therapy for the arrhythmia should be dictate d by the need to control symptoms. Symptomatic treatments include rate -control medications and strategies designed to terminate and prevent arrhythmia recurrence. Digoxin, beta-adrenergic blockers, verapamil, a nd diltiazem slow excessive ventricular rates in patients with AF and may favorably manage comorbid conditions. The efficacy of antiarrhythm ic medications is only 40 to 70% per year in preventing recurrences of AF, and these agents, except amiodarone, may increase the risk of sud den death in patients with certain types of organic heart disease and AF. The use of nonpharmacologic symptomatic therapies such as atrioven tricular node modification or ablation with a rate-response pacemaker or surgical intervention is increasing.