Atrial fibrillation, the most common type of heart arrhythmia in adults, increases the risk of thromboembolism and stroke. This rapid, irregular heart beat can be caused by a variety of conditions ranging from coronary artery disease and hypertension to surgery and hyperthyroidism. The good news is that many medications effectively treat this condition, and patients benefit similarly whether treated with a sinus rhythm-control strategy or a ventricular rate-control strategy. These are the findings from a comprehensive review of studies on the topic by the Johns Hopkins University Evidence-based Practice Center, which is directed by Neil Powe, M.D., M.P.H., M.B.A., and supported by the Agency for Healthcare Research and Quality (contract 290-97-0006).
Warfarin, an anticoagulant, significantly reduces stroke risk in these patients, unless the risk of embolism (a blood clot that breaks loose and travels to another place in the body) is low or a contraindication to anticoagulation exists. Beta-blockers (atenolol and metoprolol) and calcium-channel blockers (verapamil and diltiazem) are superior to digoxin and placebo to control heart rate, especially during exercise, when patients do not have contraindications to these therapies. Many antiarrhythmic agents are superior to placebo for acute conversion of abnormal to normal cardiac sinus rhythm. These include ibutilide, flecainide, dofetilide, propafenone, amiodarone, and quinidine.
The following medications are effective in maintaining sinus rhythm: amiodarone, propafenone, disopyramide, and sotalol. Echocardiography (ultrasound of the heart) is useful in estimating risk for thromboembolism and potentially useful in estimating likelihood of successful cardioversion of atrial fibrillation to normal cardiac sinus rhythm and maintenance of normal rhythm.
See "Management of atrial fibrillation: Review of the evidence for the role of pharmacologic therapy, electrical conversion, and echocardiography," by Robert L. McNamara, M.D., M.H.S., Leonardo J. Tamariz, M.D., M.P.H., Jodi B. Segal, M.D., M.P.H., and Eric B. Bass, M.D., M.P.H., in the December 2003 Annals of Internal Medicine 139, pp. 1018-1033.