Atrial fibrillation (AF) is the most common sustained, medically significant, and troublesome arrhythmia encountered in clinical practice. AF has been associated with decreased quality of life (symptoms), serious morbidity (thromboemboli and tachycardia-induced cardiomyopathy), and increased risk of mortality. Several articles(1,2) have reviewed this arrthymia in depth including its presentations, prognosis and management. This review will focus on new developments in the management of AF.

When a patient presents with AF, four issues must be routinely addressed. First, is there is an underlying etiology that will be self-terminating or correctable? In these cases, AF itself is not likely to become a chronic or recurring disorder. Such etiologies include pneumonia, pericarditis, thyrotoxicosis, and thoracic surgery. In the absence of such correctable or limited entities, AF is likely to recur and thus become an on-going disorder requiring significant attention over the course of time.AF may then present in paroxysmal, persistent, or permanent forms.

The second issue is ventricular rate control. In the absence of intrinsic atrioventricular (AV) nodal dysfunction, the ventricular rate during AF will be rapid, as a result of the ultrarapid (>400–600 beats per minute (bpm)) atrial rates. Control (restoration of physiologic rates) of the ventricular response is essential both for symptom reduction and to prevent the development of a tachycardia-induced dilated cardiomyopathy (which may occur with chronic rates of 90–100bpm or higher). Control is usually achieved with the administration of one or more AV nodal depressant drugs, such as a ß-blocker, verapamil, diltiazem, or digitalis. There are guidelines on their relative efficacies and the factors that should underlie the specific selection in a given patient.(3) Efficacy in each patient is best determined with a 24- hour ambulatory electrocardiograph (ECG) recorder so that the average heart rate is <90bpm, the peak ventricular rate is no greater than would be present during the same level of activity if normal sinus rhythm (NSR) were present, and the minimum rate is not excessively slow.When pharmacotherapy fails to provide adequate ventricular rate control because of either drug inefficacy or intolerance, AV node ablation and implantation of a modern rate-responsive pacemaker become the therapy of choice.Thus, rate control can be achieved in 100% of patients and is essential.

Anticoagulation is the third issue.Whether patients have paroxysmal atrial fibrillation (PAF), persistent AF awaiting cardioversion, or permanent AF, considerations regarding anticoagulation must be addressed.A simplified view of current guidelines(3) would state that the presence of recognized risk factors that indicate an increased risk for an embolic event dictate the administration of warfarin (to an international normalized ratio (INR) value of 2.0–3.0), whereas the absence of such risk factors does not, and usually results in the use of aspirin 325mg per day. Such risk markers include age >65 years, prior emboli, hypertension, diabetes, ventricular failure, rheumatic disease, and selected echocardiographic identifiers that may be useful in particular circumstances.3 When any of these risk markers is present, clinical trials have shown a greater efficacy and risk-benefit ratio for warfarin than for aspirin.

Fourth, and finally, is the issue of whether and when to pursue the return and maintenance of NSR, rather than to allow the patient to remain in AF, even if ratecontrolled and adequately anticoagulated. Clearly, if the patient continues to have symptoms from AF and a less than desirable quality of life (QOL) despite rate control, sinus rhythm must be considered. For persistent AF, cardioversion would be applied and then, as with PAF, the maintenance of NSR would be sought, initially with the use of an antiarrhythmic drug (AAD).The selection of the AAD to be employed should be guided by the now internationally developed guidelines recommended jointly by the American College of Cardiology (ACC), the American Heart Association (AHA), the European Society of Cardiology (ESC), and the North American Society of Pacing and Electrophysiology (NASPE) in October 2001.

While each of the four issues regarding AF detailed previously are well recognized and reviewed, each of them has been influenced by newer or developing forms of therapy and/or by recent clinical trial data indicating that certain additional considerations regarding these four issues now require attention.