Atrial fibrillation (AF) is the most common form of supraventricular tachycardia, a heart condition in which the upper chambers of the heart (the atria) beat irregularly and much too fast because they receive extra, "abnormal" electrical signals. This causes the atria to quiver (fibrillate), affecting the heart's ability to sufficiently pump blood to the body. As a result, your brain and other organs may not be getting the full blood supply they need.
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How common is AF? A Mayo Clinic study now estimates that over five million Americans have AF. That's more than double previous estimates of 2.2 million. The odds of developing AF increase with age - it is estimated that nearly four percent of people over age 60 and nine percent of those over 80 have AF.
What causes AF? It is unlikely your doctor can pinpoint just one cause of your AF, but there are certain risk factors that increase the likelihood of developing AF. These include:
What are the symptoms of AF? AF may produce an uncomfortable sensation in the chest. The decreased pumping power of the heart can also cause dizziness, lightheadedness, shortness of breath, lack of stamina and fatigue. Some patients, however, have no sensation at all that their heart is fibrillating.
How is AF diagnosed? AF can be detected through an electrocardiogram (EKG or ECG) which records electrical signals generated by the heart. A monitor may also be worn for one or more days to detect AF.
Why should I treat AF? AF is a dangerous medical condition that becomes more difficult to treat over time. It causes the heart to lose its ability to work effectively and can lead to irreversible heart damage. AF can also lead to the formation of blood clots inside the heart, which may lead to a stroke. In fact, AF patients are twice as likely to die and five times more likely to have a stroke. Medications can alleviate the symptoms of AF, but they do not cure the underlying problem.
How is AF treated? AF therapy is aimed at reducing the patient's risk of stroke, relieving symptoms and trying to prevent further weakening of the heart. Unfortunately, there is no single treatment strategy that has been shown to be effective for all patients with AF.
There are several therapies that may be used alone or in combination. The choice of treatment depends upon the severity of your symptoms, the likelihood that you will respond to a particular treatment and consideration of the risks versus benefits of treatment. Your doctor can discuss your specific issues with you.
Drug therapies include blood thinners and medications used to control your heart rate during AF and restore its normal rhythm.
People who have certain conditions (atrial fibrillation, artificial heart valves), or who are undergoing certain types of surgery, are at risk for forming blood clots. Blood clots can block blood flow to an extremity, or break off and travel elsewhere in the body, causing heart attacks, strokes or pulmonary embolisms.
Anticoagulants (or blood thinners) are prescribed to most AF patients to prevent blood clots that could lead to a stroke. Coumadin®* (warfarin) is the most commonly prescribed drug and has been shown to reduce the risk of stroke by 68% compared to no treatment at all. To achieve this level of protection, however, it is important to maintain the correct level of Coumadin in your blood - too little and clots can form; too much and you can have severe bleeding problems.
As many other drugs, dietary supplements and foods can affect warfarin blood levels. It is important to follow your doctor's instructions closely and have your blood monitored regularly while taking warfarin.
The FDA recently approved Pradaxa® (dabigatran etexilate) as an anticoagulant alternative for warfarin in most AF patients, with improved effectiveness for stroke prevention at approved doses. Routine blood monitoring is not required with dabigatran etexilate, but this is not to say it is without risks. At approved doses, the risk of severe bleeding is roughly equivalent to warfarin in scientific studies. The dose of dabigatran etexilate should be reduced in patients with severe kidney dysfunction, and caution may be warranted with the usual dose given to patients who are frail and elderly. Your doctor will help you decide which drug is right for you.
Anticoagulation Clinic pharmacists, working with your doctor, monitor and adjust anticoagulation therapy to maximize the benefits and minimize the risks associated with therapy, as well as provide information on medication-related issues. Clinics of these types have been very effective at helping doctors provide the highest-quality care to their patients.
Rate Control drugs try to control your heart rate during AF and Rhythm Control drugs (antiarrhythmics) try to bring your heart back into a normal and consistent rhythm. These drugs can offer a degree of success, but some people have problems tolerating their side effects or cannot use them because they may interact with other drugs they are taking.
Ablation therapies use various surgical techniques to eliminate the main causes of AF.
Ablation techniques are:
As with any cardiac procedure, there are varying degrees of risk involved. Your doctor can help you understand what they are and how your overall health and age affect these risks.
