Management of AF
Management of AF is directed at:
- Treating underlying causes, if found
- Reducing symptoms of AF
- Reducing risk of stroke
- Reducing elevated heart rates
Aspirin, warfarin, or certain newer agents (Pradaxa) are used to reduce stroke risk, which is by far the most concerning problem associated with AF. Beta blockers, calcium channel blockers, or digoxin are given to control heart rates. This proven strategy (“Rate Control plus Anticoagulation”) works for most patients; consequently most do not need catheter ablation or surgery.
Amazingly, about half of patients with AF have no symptoms at all. Those who do have symptoms, however, may feel better using an approach that attempts to maintain normal sinus rhythm (“Rhythm Control plus Anticoagulation”) by medications or procedures. A discussion of these two approaches to the management of AF follows.
Primary Strategies: “Rate Control” vs. “Rhythm Control”
Because the main problem with AF is stroke, and because a stroke can be so devastating, great efforts are made to try to prevent it. Stroke is the main cause of disability in the US, and the third most common cause of death. Blood thinners are the mainstay of therapy of AF. Older patients, or those with congestive heart failure, diabetes, high blood pressure, or a previous stroke are at risk and usually are best treated with the blood thinner warfarin (Coumadin). Some may have none of these risk factors and are at low risk of stroke; these patients may be safely treated with aspirin instead of warfarin. Aspirin is a very mild blood thinner but does not prevent strokes as well as warfarin. Plavix may have some effect. Promising and effective new blood thinners (ximelagatran, dabigatran) are not yet approved by the FDA so are not available in this country. No other medications, dietary maneuvers, or herbal products have been shown to prevent strokes, including those thought to “thin the blood”.
Once anticoagulation has been established, then the decision must be made to allow AF to persist, and make sure that heart rates are maintained in a reasonable range (“Rate Control plus Warfarin Strategy”), or to try to maintain normal sinus rhythm (“Rhythm Control plus Warfarin Strategy”). These two strategies have been compared (AFFIRM trial; Wyse 2002); patients do about as well with either strategy in most cases.
Rate Control Plus Anticoagulation Strategy
Medications to keep heart rates down in the normal range are important because symptoms of AF are related to the rapid and irregular beating of the ventricles. Persistently elevated heart rate can weaken the heart as well (cardiomyopathy). Medications such as beta blockers (metoprolol, atenolol, others), calcium channel blockers (verapamil, diltiazem, others) or digoxin are used in an effort to keep heart rates normal.
The combined approach of “Heart Rate Control plus Blood Thinners” has been shown to be the best approach to treating AF for most patients, but other approaches are appropriate in some circumstances; these are described below.
Rhythm Control Plus Anticoagulation Strategy
Pill in the Pocket
“Pill in the pocket” is the term for taking a single dose of medication (flecainide (Tambocor) or propafenone(Rhythmol)) just when an episode occurs. It is best for patients with infrequent episodes of “persistent” AF – that is, AF that continues until treated, and normal rhythm continues for weeks or months after treatment. For the first trial of this approach, you must be observed in the clinic, emergency room or hospital. If it is effective at that time, and you don't have problems with the medicine, this is a safe and effective way to manage intermittent AF.
Medications to prevent AF: Several medications are available (flecainide (Tambocor), sotalol ( Betapace), dofetilide (Tikosyn), amiodarone (Pacerone), dronedarone (Multaq)) that can prevent AF in some patients. Although many patients do well with this approach, these medications are only moderately effective and are associated with side effects in some patients.
Cardioversion is a procedure in which an electrical charge resynchronizes the heart so that it beats regularly again. It’s best for those with prolonged continuous (“persistent”, “permanent” or “chronic”) atrial fibrillation. It is performed when a patient is sedated, and most patients do not feel or remember it. It almost always works, but normal rhythm may be maintained only for minutes or hours. In other patients, it may last months or even years. Although one would think that returning to normal rhythm would eliminate the risk of stroke, it has been shown that AF can return without any symptoms, and for that reason blood thinners usually continue to be required. Still, most physicians believe that cardioversion should be considered at least once in patients with persistent AF, and many patients will safely undergo cardioversion many times. It is generally safe and does not hurt the heart. Cardioversion should generally be considered within the first 48 hours or so of the onset of AF if you have not been taking blood thinners (warfarin, Coumadin), as there may be a risk of stroke if you wait longer.
Pacemakers are excellent therapy for slow heart rates, but they don’t do anything for the rapid heart rates usually seen with AF. If heart rate cannot be controlled with medications, it is sometimes best to implant a pacemaker, then eliminate the electrical connection between the upper and lower chambers (“Ablation of AV Node plus Pacemaker”) so that the AF does not cause the lower chambers to beat abnormally. Although the atrial fibrillation (which is in the upper chambers) will still be present, the heart rate (lower chambers) is then controlled by the pacemaker and consequently will be entirely regular and at normal rates. People usually feel better following this, and can often eliminate some of the medications that were used to try to slow down the heart rate. However, because the AF is still present, risk of stroke continues, and blood thinners are needed.
Advanced Therapy: Catheter Ablation and Minimally Invasive Surgery
Advanced therapy of AF refers to procedures intended to permanently cure atrial fibrillation, including the many varieties of the surgical and "catheter maze" (catheter ablation) procedures. These include procedures involving advancing a catheter into the heart from a vein in the leg in order to cauterize and eliminate the spots from which the AF arises (“Catheter Ablation of AF”), and cardiac surgical procedures in which these areas are cauterized through incisions between the ribs (“Minimally Invasive Surgery of AF” or "mini-maze"). You can read more about these procedures beginning at the Procedures page.
AF: What should you do about it?
Atrial fibrillation needs to be addressed carefully, with special attention to the risk of stroke, which is by far the worst problem. Your primary physician has a great deal of experience with it, and should be consulted first. Your physician will:
- Address potential causes of AF such as high blood pressure
- Identify and treat sleep apnea, a commonly overlooked cause of AF
- Recommend lifestyle changes such as limiting intake of alcohol and caffeine
- Estimate your risk of stroke from AF, and start blood thinners if appropriate
- Keep your heart rate in a reasonable range with medications
- Consider cardioversion, antiarrhythmic medications, or other options
- Refer you to a cardiologist or an electrophysiologist (heart rhythm specialist) if you have a particularly difficult or unusual case, or to consider advanced, potentially curative therapy such as catheter ablation or surgery.