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Atrial fibrillation – Be pulse aware
Atrial fibrillation (AF) is a condition involving an irregular heart rhythm, known as an arrhythmia. It is the most common type of arrhythmia, affecting approximately 350,000 Canadians. Generally, the risk of developing AF increases with age and with other risk factors such as diabetes, high blood pressure, and underlying heart disease. One of the main complications of atrial fibrillation is stroke. Individuals with atrial fibrillation have a risk of stroke that is 3 to 5 times greater than those without AF.
Some people with atrial fibrillation may feel perfectly fine. They may not even know they have the condition until they have a routine test called an electrocardiogram (described below). Others with atrial fibrillation may experience various symptoms including:
Actions you can take:
An overview of atrial fibrillation
Atrial refers to the top two chambers of the heart known as the atria, where the irregularity in atrial fibrillation occurs. Atrial fibrillation falls under a larger category of illnesses called arrhythmias, which are electrical disturbances of the heart. Arrhythmias can also occur in the ventricles, the two chambers below the atria, and these tend to be more serious than arrhythmias affecting the atria.
The atria (the heart's "collecting chambers") are designed to send blood efficiently and rhythmically into the ventricles (the "pumping chambers") by way of regular electrical signals. From there, blood is pumped to the rest of the body. In atrial fibrillation, the electrical signals are rapid, irregular and disorganized, and the heart may not pump as efficiently.
Atrial fibrillation can cause the heart to beat very fast, sometimes more than 150 beats per minute. A faster than normal heartbeat is known as tachycardia.
Read more about the anatomy of the heart.
Although untreated atrial fibrillation can cause considerable impairment of quality of life, the majority of patients with AF lead active, normal lives with treatment. Be sure to consult your doctor if you have atrial fibrillation but continue to feel unwell.
Atrial fibrillation (AF) has different forms
What causes atrial fibrillation?
Quite often, the cause of atrial fibrillation is not known. Here are a few conditions that might lead to AF:
How do I know if I have atrial fibrillation?
Some people with atrial fibrillation may feel perfectly fine. They may not know they have the condition until they have a routine test called an electrocardiogram (described below).
To hear what atrial fibrillation sounds like, listen to this audio file.
Others with atrial fibrillation may experience various symptoms including:
How is atrial fibrillation diagnosed?
If your pulse is fast and your heartbeat is irregular, your doctor may have you checked for atrial fibrillation. Your doctor will take your medical history, and will ask you for details about your condition and risk factors. Questions may include: How long have you had symptoms? Describe your symptoms. Do they come and go? Do you have other medical conditions? How much alcohol do you drink? Your doctor will also ask you whether anyone in your family has atrial fibrillation, and whether you have heart disease or a thyroid condition. Your age is also a factor to take into consideration, as AF is more common in older people.
Stethoscope Using a stethoscope, your doctor will listen for fast, irregular beats. Your doctor will also check your pulse and determine whether or not it is normal.
To hear what atrial fibrillation sounds like, listen to this sound file.
Electrocardiogram The main diagnostic test is an electrocardiogram (ECG), which is a painless procedure performed in a clinical setting. Small electrodes are attached to your arms, legs, and chest, and the machine charts the electrical activity of your heart. Your doctor can determine what type of arrythmia is causing an irregular heartbeat from the printout provided by the electrocardiogram. Read more about electrocardiogram.
Echocardiogram A painless procedure, an echocardiogram uses sound waves to make a picture of your heart. Read more about echocardiogram.
Holter monitor To test the rhythm of your heart while you do regular daily activities, you may be asked to wear a Holter monitor for 24 hours. This is a small, portable device that is strapped to your body. It records the electrical activity of your heart during physical activity and while at rest.
Event monitor This electrical device, which is strapped to your body, monitors your heartbeat only when you turn it on to record your symptoms. It is generally worn for one or two weeks at a time.
Blood tests Your doctor may also order blood tests to rule out thyroid disease or other blood chemistry abnormalities. Read more about blood tests.
How is atrial fibrillation treated?
Your physician will help decide what is the best approach to treat your atrial fibrillation. Your doctor will customize the treatment to your needs, based upon your risks, medical profile and how much the symptoms are interfering with your quality of life.
Most patients with atrial fibrillation will likely have to take blood thinners in order to reduce the risk of stroke. The risk of stroke depends on several other risk factors, including the presence of heart muscle weakness, having high blood pressure or diabetes, being over 75 years of age, or having had a previous stroke or a mini-stroke (TIA). Accordingly, your doctor may prescribe blood thinners such as an anti-platelet like ASA (Aspirin®) or an anticoagulant to prevent clots from forming and travelling to the brain.
There are two general strategies for the treatment of atrial fibrillation - rhythm control and rate control. Your doctor will decide which strategy is best for you based on your symptoms and other factors.
When taking medications of any type, it is important to follow your doctor or pharmacist's instructions. Establish a routine for taking your pills, and keep to your daily schedule. Do not share medications with others, and do not stop taking your medication without consulting your doctor. Report any side effects to your doctor, because he or she may change the dosage or type of medication to prevent or reduce any side effects.
Electrophysiology Studies (EPS) and Catheter Ablation On rare occasions, patients with atrial fibrillation who do not respond to medications or electrical cardioversion require an EPS in order to stop atrial fibrillation from recurring. The objective of EPS testing is to locate the cause of irregular electrical impulses in the heart. Catheter ablation is then performed to destroy, through tiny burns, the electrically chaotic tissue in the heart. During EPS and catheter ablation, thin wires (or catheters) are introduced to the heart through veins in the leg and neck. Radiofrequency energy is sent through the catheters to the parts of the heart where the irregular electrical impulses are located. Ablation essentially creates scars in the heart that stabilize any electrical short circuits.
Can those under 60 have atrial fibrillation?
If you develop atrial fibrillation and do not have any structural heart disease, this is considered idiopathic (or lone) AF. Idiopathic AF usually occurs before the age of 60.
Researchers have so far identified a handful of genes that predispose families to atrial fibrillation. Once all these genes are identified, researchers may be able to develop new treatments for this condition. Those who have a genetic predisposition to Idiopathic AF may develop the disease in their 30s and 40s. It is also possible for young people who do not have AF in their family to develop the disease.
What can you do?
Healthy lifestyle changes are always a good idea. Your risk for developing many diseases can be reduced if your diet is lower in saturated and trans fats, and includes plenty of vegetables, fruit, fibre and lean protein. Quitting smoking, limiting alcohol intake and reducing stress as much as possible have been shown to improve health in numerous studies. Any lifestyle changes that lower blood pressure (such as maintaining a normal weight) are likely to reduce the chances of developing AF.
It may be possible to prevent atrial fibrillation by staying physically active. A large study of people over the age of 65 found that participating in light to moderate physical activities, particularly leisure-time activities such as gardening and walking, were associated with significantly lower AF incidence. Even if you have AF, it is important to stay physically active because doing so has a positive impact on your overall health. Consult your doctor before you become more physically active.
Visit your doctor regularly to have your atrial fibrillation monitored. Do not attempt to monitor your own heart rhythm by using expensive, high-tech equipment you may find on the internet. Using such products may unnecessarily elevate stress.
If you have high blood pressure, ask your doctor how to monitor your own blood pressure at home.
Is there a connection between atrial fibrillation and stroke?
AF increases your risk of stroke. It is estimated that up to 15% of all strokes are caused by atrial fibrillation. This risk increases with age, so that after age 60, one-third of all strokes are caused by atrial fibrillation. Also, individuals with atrial fibrillation have 3 to 5 times greater risk for ischemic stroke.
With a normal heart rhythm, the heart receives electrical signals from the brain via the sinoatrial (SA) node. The SA node sends impulses to the atria which instructs them to beat. The impulses then make their way to the lower chambers of the heart (the ventricles), which pump blood to the rest of the body.
During atrial fibrillation, the atria contract chaotically and in a disorganized manner. Because the atria don't move blood properly, blood pools and gets stuck in the grooves of the heart. This may result in the formation of blood clots, which could get pumped to the brain and result in an ischemic stroke. An ischemic stroke is caused when blood flow to the brain is interrupted by a clot in one of the blood vessels within, or leading to, the brain. Studies show that long-term use of the blood thinner warfarin in patients with AF can reduce the risk of stroke by 70 to 80%.
For more information about AF please download Atrial fibrillation: the heart of the matter (PDF, 4MB)
Atrial fibrillation awareness events
The Heart and Stroke Foundation is raising awareness of Atrial Fibrillation and its impact on health. Canadians will have an opportunity to learn more about atrial fibrillation through awareness events across the country.
We thank the following sponsors for providing the funds to make these events possible. Acceptance of financial support by the Heart and Stroke Foundation does not constitute an endorsement.
Last Modified August 2011