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The heart usually beats in a regular rhythm. Atrial fibrillation (AF) occurs when the upper chambers of the heart (the atria) beat in an irregular and uncoordinated way, called fibrillation. The heart rate in AF may sometimes be much faster than normal.
Almost 2.5 million people in the United States have AF. Although it usually occurs in people over 60, it can occur in younger adults too.
People with AF may feel their heart pounding or palpitating, or note an irregular pulse. AF may also cause weakness, inability to exercise, shortness of breath, chest discomfort, dizziness, or fainting. However, some people with AF don’t have any symptoms at all.
Because the atria are not beating normally, AF increases the risk that a blood clot may form in the heart. These clots can flow up to the brain and cause a stroke. However, the good news is that the risk of stroke with AF can be substantially reduced with proper treatment.
Your doctor might order an electrocardiogram (ECG) to evaluate your heart rate and rhythm, and blood tests to investigate possible causes of your AF. You may also be asked questions to assess your risk of stroke. This will help decide what treatment might be best for you.
Some conditions that cause AF can be treated, such as an overactive thyroid. But often, no underlying cause is found, and the goal becomes management of the heart’s rate and/or rhythm, and the prevention of clots.
There are four major goals for managing AF:
Several medicines can slow down the heart rate in AF if it is too rapid. These include beta-blockers, calcium channel blockers, and digoxin. Your doctor can decide which is best for you.
Some medications can help the heart go back into a normal rhythm. They may not be needed for people whose heart rates can be slowed down enough with heart rate medications.
If AF is not controlled with drugs, several procedures can help the heart return to a normal rhythm. These include giving an electric shock through the skin (cardioversion) or doing an invasive procedure known as ablation therapy to eliminate the abnormal heart rhythm.
This is one of the most important parts of managing AF. Although untreated AF raises the risk of stroke, anticoagulant medications can reduce that risk by two-thirds. Several drugs, including aspirin and warfarin (Coumadin), thin the blood to reduce the risk of blood clots and stroke. The decision on whether to use a drug, and which drug to use, is based on your risk of stroke and other factors. All these medicines can cause bleeding, and have to be closely monitored by your doctor.
For more information on AF, see the Heart Rhythm Society website at http://www.hrsonline.org/PatientInfo/HeartRhythmDisorders/AFib/index.cfm