(Circulation. 2008;117:e340-e343.)
© 2008 American Heart Association, Inc.
Cardiology Patient Page |
From the Brigham and Womens Hospital, Boston, Mass (J.B.S.) and East Carolina University, Greenville, NC (S.F.S.).
Correspondence to Julie B. Shea, Brigham and Womens Hospital, Cardiovascular Division, 75 Francis St, Boston, MA 02115. E-mail jshea{at}partners.org
| Introduction |
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| How Is Atrial Fibrillation Diagnosed? |
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| Symptoms Associated With Atrial Fibrillation |
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| Who Gets Atrial Fibrillation? |
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| Anticoagulation |
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One way to prevent blood clots from forming is by thinning the blood with a medication that reduces clotting. This is a process called anticoagulation. The medications used include aspirin or warfarin sodium (Coumadin, Bristol-Myers Squibb, Princeton, NJ). Several large-scale clinical trials have demonstrated that anticoagulation with warfarin reduces the risk of stroke in patients with atrial fibrillation.
Warfarin is taken daily by mouth. Unlike most medications, the dose of warfarin is adjusted according to blood test results; therefore, the dose may change over time. The blood test used to monitor the thinness or thickness of the blood is referred to as the INR, or International Normalized Ratio. It is important to monitor the INR (at least once a month for most patients) to ensure that the level of warfarin is in the effective range. If the INR is too low, blood clots will not be prevented, and if the INR is too high, there is an increased risk of bleeding.
| Treatment of Atrial Fibrillation |
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Heart Rate Control
During AF, the atria are beating quickly and irregularly, often times in excess of 350 to 500 times per minute. The impulses are transmitted to the ventricles over an electrical bridge called the atrioventricular (AV) node. Fortunately, the AV node slows the transmission of many of these impulses; however, the ventricular rate can still be quite rapid (more than 100 beats per minutes) and, if left untreated, can result in the development of heart failure. Rate control is very important. Medications such as beta-blockers, calcium channel blockers, and digitalis can be used to help slow conduction of electrical impulses over the AV node to maintain a heart rate less than 80 beats per minute at rest.
Heart Rhythm Control: Maintaining a Normal Rhythm
Restoration of a normal heartbeat is often attempted for those individuals with symptomatic AF. Medications called antiarrhythmic drugs are used to stabilize the electrical activity in the atria in an attempt to prevent episodes of AF. If AF is persistent and does not stop by itself, electrical cardioversion can be performed to restore the normal rhythm. Although cardioversion works immediately, it does not prevent the AF from recurring; medications, ablation, and surgery are potential treatments to try to prevent AF from recurring.
Electrical Cardioversion
Cardioversion3 is a procedure whereby a brief electrical current (shock) is delivered through the chest wall to the heart through special pads or paddles that are applied to the skin of the chest. The purpose of the cardioversion is to interrupt the abnormal electrical circuit(s) in the heart to restore the normal heart beat. The delivered shock activates all the heart cells simultaneously, thereby interrupting and terminating the abnormal electrical beat (typically fibrillation of the atria). This procedure allows the electrical system of the heart to take over, restoring a normal heartbeat.
Catheter Ablation
Catheter ablation4,5 is an invasive procedure that uses special tubes (catheters) with small electrodes. After administration of a local anesthetic to numb the skin over blood vessels (usually in the groin), the catheters are inserted into the blood vessel and guided to the heart. There, they are used to cauterize (burn) or freeze heart cells to modify or destroy the abnormal electrical circuits and triggers causing AF, thereby preventing AF. Another type of catheter ablation can also be performed to control rapid ventricular rates by ablating the AV node (the bridge that allows electrical signals to travel from the atria to the ventricles). This type of ablation is usually reserved for patients who have a rapid heart rate that cannot be controlled with medications. It necessitates implantation of a permanent pacemaker6 to maintain a normal heart rate.
| Lifestyle Adjustments in Atrial Fibrillation |
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Diet
Diet is an important consideration in the management of AF, particularly if one is taking warfarin. There are many types of foods, such as green leafy vegetables and some vegetable oils, that are high in vitamin K. The liver uses vitamin K to make clotting factors that prevent excessive bleeding. Erratic consumption of foods with Vitamin K can cause the INR levels to fluctuate. This does not mean that these foods need to be avoided altogether, but care should be taken to maintain a balanced intake. There are specialized cookbooks for patients who take warfarin to assist them in preparing a variety of healthy foods while maintaining a steady daily intake of vitamin K.7
Medications
Specific over-the-counter (OTC) medications, such as nasal sprays and cold remedies, contain substances that can aggravate AF and should therefore be used cautiously and only under the advice of your physician. Similarly some herbal remedies may contain stimulants that may aggravate heart rhythm problems.
Managing Anticoagulation with Warfarin
Various medications, including prescription, OTC, and herbal preparations, can interfere with the metabolism of warfarin, resulting in an INR that is either too high or too low. Patients should always consult their prescribing practitioner, pharmacist, or anticoagulation clinic before starting, changing, or stopping any medication.
Exercise and Physical Activity
Regular physical activity is important. Before starting any exercise routine, you should consult your physician or nurse to establish what would be a safe and reasonable level of activity given your specific physical condition and capabilities. Physical activity is important for a number of reasons, including:
Patients who need medications to slow their heart rate may find that their heart rate does not increase as much as they expect with exercise. This observation usually indicates that the medications are doing a good job of controlling the heart rate and the beneficial effects of exercise will still occur.
| Coping with Atrial Fibrillation |
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Below we describe a set of strategies for AF patients to use to reduce the effects of stress.
Know Your Condition
Understanding your condition allows you to communicate your needs to family, friends, and healthcare providers. Being smart about your condition is empowering. If you dont have the answer, ask your healthcare provider.
Be Mindful of Your Emotional Health
Many AF patients believe that they are the only ones who are experiencing worry or anticipatory fear. However, most AF patients experience at least some periods of fear and depression. Talking with a health professional about these concerns is another part of complete health care.
Plan Some Relaxation
Feelings of depressed mood or anxiety can lead to feelings of lack of control over ones own life. To break the cycle, you will likely need a deliberate plan to schedule pleasant events. Make and follow a plan, even though you may not want to. It makes sense that when you start doing pleasant, fun or rewarding activities again, you might start feeling a bit more like your usual self.
| Additional Resources |
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| Acknowledgments |
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None.
| Footnotes |
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| References |
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2. The AFFIRM Investigators. Relationships between sinus rhythm, treatment, and survival in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study. Circulation. 2004; 109: 1509–1513.
3. Shea JB, Maisel WH. Cardioversion. Circulation. 2002; 106: e176–e178.[CrossRef][Medline] [Order article via Infotrieve]
4. Ames A, Stevenson WG. Catheter ablation of atrial fibrillation. Circulation. 2006; 113: e666–e668.
5. Miller JM, Zipes DP. Catheter ablation of arrhythmias. Circulation. 2002; 106: e203– e205.[CrossRef][Medline] [Order article via Infotrieve]
6. Wood MA, Ellenbogen KA. Cardiac pacemakers from the patients perspective. Circulation. 2002; 105: 2136–2138.
7. Desmarais R, Golden G, Beynon G. The Coumadin Cookbook: A Complete Guide to Healthy Meals When Taking Coumadin. Salisbury, MD: Marsh Publishing; 2003.
8. Hansson A, Madsen-Hardig B, Olsson SB. Arrhythmia-provoking factors and symptoms at the onset of paroxysmal atrial fibrillation: a study based on interviews with 100 patients seeking hospital assistance. BMC Cardiovasc Disord. 2004; 4: 13.[CrossRef][Medline] [Order article via Infotrieve]
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