The prevalence of atrial fibrillation (AF) increases with age. As the population 
ages, the burden of AF increases. AF is associated with an increased incidence 
of mortality, stroke, and coronary events compared to sinus rhythm. AF with a 
rapid ventricular rate may cause a tachycardia-related cardiomyopathy. Immediate 
direct-current (DC) cardioversion should be performed in patients with AF and 
acute myocardial infarction, chest pain due to myocardial ischemia, hypotension, 
severe heart failure, or syncope. Intravenous beta blockers, diltiazem, or 
verapamil may be administered to reduce immediately a very rapid ventricular 
rate in AF. An oral beta blocker, verapamil, or diltiazem should be used in 
persons with AF if a fast ventricular rate occurs at rest or during exercise 
despite digoxin. Amiodarone may be used in selected patients with symptomatic 
life-threatening AF refractory to other drugs. Digoxin should not be used to 
treat patients with paroxysmal AF. Nondrug therapies should be performed in 
patients with symptomatic AF in whom a rapid ventricular rate cannot be slowed 
by drugs. Paroxysmal AF associated with the tachycardia-bradycardia syndrome 
should be treated with a permanent pacemaker in combination with drugs. A 
permanent pacemaker should be implanted in patients with AF and symptoms such as 
dizziness or syncope associated with ventricular pauses greater than 3 seconds 
which are not drug-induced. Elective DC cardioversion has a higher success rate 
and a lower incidence of cardiac adverse effects than does medical cardioversion 
in converting AF to sinus rhythm. Unless transesophageal echocardiography has 
shown no thrombus in the left atrial appendage before cardioversion, oral 
warfarin should be given for 3 weeks before elective DC or drug cardioversion of 
AF and continued for at least 4 weeks after maintenance of sinus rhythm. Many 
cardiologists prefer, especially in elderly patients , ventricular rate control 
plus warfarin rather than maintaining sinus rhythm with antiarrhythmic drugs. 
Patients with chronic or paroxysmal AF at high risk for stroke should be treated 
with long-term warfarin to achieve an International Normalized Ratio of 2.0 to 
3.0. Patients with AF at low risk for stroke or with contraindications to 
warfarin should be treated with aspirin 325 mg daily.