Atrial fibrillation causes an irregular heartbeat that can lead to a stroke or heart failure if left untreated. Find out what causes atrial fibrillation, the treatment options available, and how to detect atrial fibrillation.
What is Atrial Fibrillation?
Atrial fibrillation (AF) is a disorder of the rhythm of the heart. It is due to fast, irregular contraction of the upper chambers of the heart (the atria) resulting in a very fast and irregular heartbeat.
How Common is Atrial Fibrillation?
AF is the most common type of irregular rhythm, occurring in about 0.5 to one percent of the population. Prevalence of the condition increases with age, from 0.1 percent in patients under 55 years old to 10 percent in patients who are 80 years old and above.
Atrial Fibrillation Symptoms
If you have AF, you may suffer from:
• Irregular heartbeat or palpitations
• Chest pain
• Shortness of breath
• Feeling tired easily
• Lightheadedness and fainting (in rare cases)
Some patients may suffer from complications of AF such as heart failure or stroke. Others may have no symptoms, detecting AF only when they see a doctor.
Atrial Fibrillation Causes
AF occurs more commonly with ageing and typically occurs if you have underlying heart disease.
The most common causes are:
• Long-standing high blood pressure
• Ischaemic heart disease (blockages in the arteries serving the heart muscle)
• Heart valve abnormalities
• Abnormalities of the heart's pumping function (heart failure)
• Sick sinus syndrome (electrical disorder of the heart resulting in a very slow or very rapid heartbeat)
• Hyperthyroidism
However, some patients may just have AF on its own, without any detectable heart disease or symptoms.
Complications of Atrial Fibrillation
Stroke
In AF, the muscular walls of the atria quiver instead of contracting forcefully. This makes it more likely for blood clots to form. If a blood clot travels through the bloodstream and blocks blood supply to parts of the brain, this may cause a stroke.
You are more likely to form blood clots if you have the following risk factors:
• Above 65 years old
• High blood pressure (hypertension)
• Diabetes
• Previous stroke
• Enlarged upper heart chamber (atrial enlargement)
• Weakened lower heart chamber (ventricle) or heart failure
• Heart valve abnormalities or past heart valve replacement surgery
Warning signs of stroke include sudden onset of any of these symptoms:
• Numbness or weakness of the face, arm or leg, especially on one side of the body
• Confusion, difficulty in speaking or understanding
• Blindness in one or both eyes
• Dizziness, loss of balance or coordination
• Severe headache with no known cause
If a blood clot blocks an artery to other parts of the body (for e.g. a kidney or a limb), it may also damage that particular region.
Cardiomyopathy
As AF results in a fast heart rate and inefficient function of the heart muscle, weakening of the heart muscle or cardiomyopathy may result. This may eventually lead to heart failure.
Symptoms of heart failure include shortness of breath, weakness, tiredness and reduced exercise tolerance. While most patients with AF may not develop blood clots or cardiomyopathy, their lives may be affected by the uncomfortable palpitations, tiredness and shortness of breath that AF causes.
How to Detect Atrial Fibrillation
AF can be diagnosed with a recording of your heart's electrical activity called an electrocardiogram (ECG). A thorough medical evaluation by a cardiologist is important.
Other diagnostic tests that may be done include:
• Blood and urine tests
• Chest X-ray
• Echocardiography (using ultrasound to image the heart to detect any abnormal heart function or structure)
Atrial Fibrillation Treatment
AF seldom causes serious or life-threatening problems, if treated appropriately.
The goals of treating AF include:
• Slowing the heart rate (rate control)
• Preventing blood clot formation (anticoagulation)
• Restoring a normal heart rhythm (rhythm control)
Control of heart rate together with anticoagulation is recommended for most patients with AF. Control of heart rhythm may be appropriate if you have symptoms and especially if you have no significant underlying heart disease.
Rhythm control may be achieved by electrical shock or drug treatment. Newer treatments for rhythm control include:
• Insertion of a pacemaker
• Removal of the area of the heart discharging abnormal signals using a special wire
• Removal of the area giving out the abnormal signals through open heart surgery
Your doctor will discuss the risks and benefits of the different atrial fibrillation treatment options with you.
Anticoagulants
Anticoagulants are drugs that prevent blood clot formation for stroke prevention. Aspirin, clopidogrel (Plavix), ticlopidine (Ticlid) or warfarin (Coumadin, Marevan) are typically used for this purpose.
Warfarin is the most effective anticoagulant but it also has the most side effects. It should not be used if you have any bleeding problems or ulcers. Blood tests are required to establish the correct dosage of warfarin needed to keep abnormal blood clots from forming, while keeping the risk of bleeding low.
If you are on warfarin, you should:
• Know your dosage
• Be aware of warning signs of potential side effects
• Inform your doctor and dentist that you are on warfarin
• Inform the doctor immediately if you notice bleeding or bruising anywhere
• Discuss any intention of pregnancy with your doctor
• Keep your eating habits similar as sudden changes can impact the effects of warfarin
A treatment strategy that works for one person may not work for another. Each person's situation is unique. If you suffer from atrial fibrillation, discuss your treatment options with your doctor.
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