Atrial fibrillation is a very fast, uncontrolled heart rhythm that occurs when the upper chambers of the heart (the atria) try to beat so fast that they quiver rather than contract. This irregular heart rate causes poor blood flow to the body and symptoms of heart palpitations (a pounding or fluttering feeling in the chest), shortness of breath, dizziness and weakness.
Atrial fibrillation is the most common cardiac arrhythmia. More than 2 million Americans have atrial fibrillation. Most people with atrial fibrillation have an increased risk of developing blood clots that may lead to stroke.
- Irregular, rapid heartbeat
- Heart palpitations (a pounding, fluttering or racing sensation in the chest)
- Weakness and fatigue
- Shortness of breath
- Dizziness and lightheadedness
- Chest pain
- May be asymptomatic
Atrial fibrillation is often caused by changes (abnormalities or damage) to the heart’s structureas a result of:
- Obstructive sleep apnea
- High blood pressure
- Heart disease
- Heart attacks
- Abnormal heart valves
- An overactive thyroid or other metabolic imbalance
- Sick sinus syndrome - this occurs when the heart’s natural pacemaker stops functioning properly
- Increasing age
- Exposure to stimulants, such as medications, caffeine, tobacco or alcohol
- Previous heart or lung surgery
How it is Diagnosed:
To diagnosis atrial fibrillation, your doctor may do the following tests:
- Electrocardiogram (EKG) - Patches with wires (electrodes) are attached to your skin to measure electrical impulses given off by your heart. Impulses are recorded as waves displayed on a monitor or printed on paper.
- Holter monitor - This is a portable machine that records all of your heartbeats. You wear the monitor under your clothing. It records information about the electrical activity of your heart as you go about your normal activities for a day or two.
- Echocardiogram - Sound waves are used to produce a video image of your heart. The image also shows the motion pattern and structure of the four heart valves, revealing any potential leakage (regurgitation).
- Blood tests - These tests help rule out thyroid problems or blood chemistry abnormalities that may lead to atrial fibrillation.
The goals of treating atrial fibrillation are to reset the heart rhythm back to normal or control the heart rate and to prevent blood clots. The following treatment options may be used:
- Treat the underlying cause - if the underlying cause of atrial fibrillation is treatable, treatment of the problem usually converts the rhythm to normal.
- Antiarrhythmics - there are a variety of medications, called antiarrhythmics, which can be used to convert the heart rhythm back to normal.
- Medications that slow the heart rate - there are a variety of medications, including beta blockers, calcium channel blockers and digoxin that can be used to slow the heart rate.
- Electrical cardioversion - a brief electrical shock is delivered through the chest interrupting the heart’s electrical activity and allowing the heart to return its normal rhythm.
- Coumadin therapy - because there is serious risk of blood clots and stroke with atrial fibrillation, most patients require anticoagulation therapy to minimize this risk.
- Ablation - destroying (ablating) the tissues and pathways that are causing faulty signals.
- Permanent pacemaker - a pacemaker is a small electronic device that is implanted under the skin and programmed to generate and regulate the heartbeat. In patients with AF, a pacemaker may be used in conjunction with medication to help control the heart rate. In addition, in patients whose AF cannot be controlled with medications, the physician may perform a procedure to interrupt the electrical connection between the atrium and ventricles. This is called an AV node ablation. Afterward, the physician would implant a pacemaker to keep the heart from beating too slowly. The patient would still be in AF but not feel it.
What are the complications of atrial fibrillation?
- Stroke - The most common complication of atrial fibrillation is a stroke caused by a blood clot that travels to the brain. Because the heart’s pumping function isn’t working properly, the blood is not completely emptied from the heart’s chambers, causing it to pool and sometimes clot. Clots may then travel in the bloodstream to the brain, were they can block blood flow to a part of the brain and cause a stroke.
- Heart failure - Atrial fibrillation alone, especially if not controlled, may weaken the heart, leading to heart failure - a condition in which your heart can’t circulate enough blood to meet your body’s needs.