Atrial Fibrillation
Atrial fibrillation (Afib or AF) is a type of irregular heart rhythm (arrhythmia). Arrhythmias are due to electrical signal disturbances of the heart. Afib is the most common arrhythmia, affecting approximately 200,000 Canadians. The risk of developing atrial fibrillation increases with age and with other risk factors such as diabetes, high blood pressure and underlying heart disease. The main complications of atrial fibrillation are stroke and heart failure.
Atrial fibrillation affects the top two chambers of the heart (the atria). Arrhythmias can also occur in the two chambers below the atria (the ventricles), which tend to be more serious than arrhythmias affecting the atria. The atria are the heart's collecting chambers. Regular electrical signals help push blood efficiently from the atria into the pumping chambers (the ventricles). From the ventricles, blood is pumped to the rest of the body. In Afib, the electrical signals are fast, irregular and disorganized, and the heart may not pump as efficiently.
Atrial fibrillation can cause your heart to beat very quickly, sometimes more than 150 beats per minute. A faster than normal heartbeat is known as tachycardia.
Most people with Afib lead active, normal lives with treatment, but untreated it can interfere with your quality of life. Talk to your doctor if you have Afib and continue to feel unwell.
Complications
Untreated atrial fibrillation puts you at a higher risk for stroke and heart failure.
- Stroke: People with atrial fibrillation have 3 to 5 times greater risk for ischemic stroke. During Afib, the atria contract chaotically. Because the atria aren’t moving blood properly, blood pools and gets stuck in the grooves of the heart. Blood clots may form, which could get pumped to the brain. An ischemic stroke is caused when blood flow to the brain is interrupted by a clot in a blood vessel in the brain.
It is estimated that one in 4 strokes after age 40 are caused by Afib.
The risk of stroke depends on several other risk factors including the presence of heart failure, having high blood pressure or diabetes, being over 40 years of age, or having had a previous stroke or a mini-stroke (TIA). Studies show that long-term use of blood thinners in patients with Afib can reduce the risk of stroke by 70 to 80%. While with the ‘old’ blood thinner, warfarin, you had to check your blood every few days or weeks and change the dose of the drug, the newer blood thinners are ‘one size fits all’ where you can take the drug without having to check your blood periodically. These drugs are both more effective at preventing stroke than warfarin and less likely to give you a bleeding problem.
Over the years, we have learned that atrial fibrillation develops when extra beats or electrical impulses come out of the vein that drains blood from the lungs into the heart. Atrial fibrillation ablation is a procedure where your doctor would place catheters, long wires, into the heart through the intravenous placed in your groin to cauterize or freeze the tissues around these veins and prevent further Afib. If you are feeling unwell with your atrial fibrillation, please talk to your PACE doctor about ablation and other advanced treatments that are now available for this condition.
- Heart failure: Atrial fibrillation can also lead to heart failure. Heart failure is a condition in which your heart can't circulate enough blood to meet your body's needs, excess blood then backs up into the lungs and causes congestion. The lungs fill with water, ankles swell and you find it difficult to do your usual activities due to shortness of breath. Afib’s irregular, fast heart beat leads to ineffective pumping of the blood which – especially if not controlled – may weaken the heart.
Types of Atrial Fibrillation
- Paroxysmal: temporary episodes that come and go. They start suddenly and then the heart returns to a normal beat on its own without medical assistance, usually within 24 hours.
- Persistent: episodes that last longer than seven days. Usually treatment is needed to return the heart to a normal rhythm.
- Permanent: the irregular heart rhythm lasts for more than a year despite medications and other treatments. Some people with permanent Afib do not feel any symptoms or require medications.
Causes
Common causes of Afib include:
- High blood pressure – the most common risk factor for Afib
- Heart failure
- Coronary artery disease which has led to a heart attack
- Coronary artery bypass surgery or valve repair or replacement surgery
- Cardiomyopathy
- Diabetes
- Myocarditis or pericarditis – infection or inflammation of the heart
- Diseases that damage the valves of the heart
- Hyperthyroidism – overactive thyroid
- Pulmonary embolism – a blood clot in the lung
- Atrial septal defect (repaired in childhood) and other congenital heart defects
- Heavy alcohol use
- Unhealthy weight
- Sleep apnea
- Age – Afib is more common in older people
In many cases, the cause of atrial fibrillation is not known.
If you develop Afib before the age of 60 without any history of heart disease, you may have idiopathic (or lone) atrial fibrillation. Researchers have identified a handful of genes that predispose families to idiopathic Afib.
It is also possible for young people without Afib in their family to develop the disease. If this applies to you, please talk to your PACE doctor about genetic testing which is now available.
Symptoms
Some people with Afib may feel fine and not know they have the condition until it is found in a routine test called an electrocardiogram (ECG). Other people have symptoms. The symptoms affect people in different ways. If you are experiencing any of these Afib symptoms, visit your doctor.
- Palpitations – this might feel like your heart is racing, beating irregularly or flip-flopping in your chest.
- Feeling very tired/having no energy – you may feel short of breath or weak with the slightest physical effort. These symptoms may take some time to develop. A number of patients with atrial fibrillation attribute these to age or poor conditioning. Even if this were partially true, most patients benefit from at least a trial of normal rhythm to see whether they feel better and have more energy in normal rhythm compared to atrial fibrillation.
- Chest discomfort
- Feeling light-headed or dizzy
- Sweating
- Feeling anxious
- Trouble concentrating
If you are experiencing chest discomfort or other signs of a heart attack, call 9-1-1 or your local emergency number immediately.
Diagnosis
If your pulse is fast and your heartbeat is irregular, your doctor may check you for Afib. They will take your medical history and question you about symptoms and risk factors.
Questions may include:
- How long have you had symptoms? Describe them. Do they come and go?
- Do you have other medical conditions?
- How much alcohol do you drink?
- Does anyone in your family have Afib?
- Do you have heart disease or a thyroid condition?
Tests include:
- Physical exam
- Electrocardiogram (ECG/EKG)
- Echocardiogram
- Holter or event monitoring
- Blood tests
- Stress test (Exercise electrocardiogram and / or echocardiogram)
Treatment
Your treatment will be based on your risks, medical profile, needs, preferences and how much symptoms are interfering with your quality of life.
First, your doctor will talk to you about using blood thinners to prevent stroke. As far as Afib itself is concerned, there are two general treatment strategies – rate control and rhythm control. Your doctor will determine which strategy is best for you based on your symptoms and other factors.
Rate control:
- Almost every patient with atrial fibrillation will be prescribed a medication to slow their heart rate. For some people, this type of medication is enough to control their symptoms.
Rhythm control:
- This is an attempt to prevent an irregular heartbeat by restoring and maintaining a normal, regular heartbeat. The first step is medication to prevent the Afib from occurring. Since symptoms of atrial fibrillation such as fatigue may take some time to develop, a number of patients with atrial fibrillation attribute these to age or poor conditioning. Even if this were partially true, for most patients benefit from at least a trial of normal rhythm to see whether they feel better and have more energy in normal rhythm compared to atrial fibrillation.
Some patients may also require an electrical cardioversion. This is a controlled electric shock to the heart to restore a normal rhythm. On rare occasions medications and electrical cardioversion do not work. You may be referred to a specialist and considered for an electrophysiology study and catheter ablation to stop the Afib from recurring.
Medications
The medications used for atrial fibrillation are:
Blood thinners:
- Reduce the risk of stroke. While with the ‘old’ blood thinner, warfarin, you had to check your blood every few days or weeks and change the dose of the drug, the newer blood thinners are ‘one size fits all’ where you can take the drug without having to check your blood periodically. These drugs are both more effective at preventing stroke than warfarin and less likely to give you a bleeding problem. Other medications such as aspirin and other anti-platelet medications are generally not indicated for patients with atrial fibrillation.
Beta blockers, calcium channel blockers, and digoxin:
- Help slow the heart rate and allow it to fill properly with blood.
Anti-arrhythmics:
- Drugs that prevent abnormal heartbeats and help restore normal rhythm.
Surgeries and other procedures:
- Cardioversion therapy: Electrical pulses are sent through paddles to the heart to jolt the heart back into normal rhythm. Cardioversion is similar to defibrillation, but uses much lower levels of electricity.
Catheter ablation:
- Over the years we have learned that atrial fibrillation develops when extra beats or electrical impulses come out of the vein that drain blood from the lungs into the heart. Atrial fibrillation ablation is a procedure where your doctor would place catheters, long wires, into the heart through the intravenous placed in your groin to cauterize or freeze the tissues round these veins and prevent further Afib. Ablation creates scars in the heart that stabilize the electrical short circuits.
If you are feeling unwell with your atrial fibrillation, please talk to your PACE doctor about ablation and other advanced treatments that are now available for this condition.
Implantable pacemaker:
- A surgically implanted device that helps regulate heart rate and rhythm by using electrical pulses to prompt the heart to beat at a normal rhythm. This strategy is frequently combined with ablation targeting your normal conduction system – the AV node or AV junction – in order to provide rate control, while having the pacemaker maintain your heart beat after the conduction system has been destroyed.
Lifestyle
You can lower your risk of developing other heart diseases and stroke by knowing and controlling your blood pressure, diabetes and blood cholesterol. It’s also important to lead a healthy lifestyle.
- Be smoke-free.
- Be more active.
- Aim for a healthy weight
- Eat a healthy balanced diet
- Drink lots of fluids
- Drink less alcohol and caffeine
- Manage stress.
Living with atrial fibrillation
Get emotional support:
- It’s normal to feel worried or afraid after a diagnosis of heart disease. Find someone you can turn to for emotional support like a family member, friend, doctor, mental health worker or support group.
Don’t be afraid to exercise:
- Sometimes people feel they can’t exercise with atrial fibrillation because they don’t feel well or they are afraid. As long as you are feeling well, you can still exercise. If you have atrial fibrillation, staying physically active will have a positive impact on your overall health. Talk to your doctor before you become more physically active. If you do exercise, consider getting a device such as a Fitbit or an Apple watch which can monitor your heart rate and aim to maintain a heart rate below 85% or 220 - (your age)
Manage your blood pressure:
- High blood pressure is a risk factor for stroke and other heart-related problems, in addition to being a risk factor for atrial fibrillation.
Visit your doctor regularly:
- To have your atrial fibrillation monitored.
Cardiac rehabilitation:
- A personalized program of exercise, education and counselling to help you recover from heart disease and reduce your risk of having other heart problems in the future. Talk to your doctor about how to find a program in your area or contact your public health department or hospital.