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Atrial fibrillation (A-fib) is an arrhythmia (an irregular and often very rapid heart rhythm) that can result in blood clots in the heart. Stroke, heart failure, and other heart-related complications are all increased by A-fib.
During atrial fibrillation, the upper chambers of the heart (the atria) beat chaotically and irregularly, out of sync with the lower chambers (the ventricles). Many people with A-fib have no symptoms. A-fib, on the other hand, can cause a fast, pounding heartbeat (palpitations), shortness of breath, or weakness.
Atrial fibrillation episodes can be intermittent or persistent. Although A-fib is rarely fatal, it is a serious medical condition that necessitates prompt treatment to avoid a stroke.
Medication, therapy to reset the heart rhythm, and catheter procedures to block faulty heart signals may all be used to treat atrial fibrillation.
A person who has atrial fibrillation may also have atrial flutter, which is a related heart rhythm problem. Although atrial flutter is a distinct arrhythmia, treatment is very similar to that of atrial fibrillation.
WHAT ARE THE SYMPTOMS OF ATRIAL FIBRILATION?
Some people with atrial fibrillation (A-fib) are asymptomatic. Those who do have atrial fibrillation symptoms may experience the following signs and symptoms:
- Feelings of a racing, fluttering, or pounding heart (palpitations)
- Chest pain
- Dizziness
- Fatigue
- Lightheadedness
- Lowered ability to exercise
- Breathing difficulty
- Weakness
Atrial fibrillation could be:
- Occasional (paroxysmal atrial fibrillation): A-fib symptoms come and go, lasting anywhere from a few minutes to several hours. Symptoms can last up to a week at times, and episodes can occur repeatedly. Symptoms may subside on their own. Some people with sporadic A-fib require treatment.
- Persistent: The heart rhythm does not return to normal with this type of atrial fibrillation. If a person experiences A-fib symptoms, cardioversion or medication treatment may be used to restore and maintain a normal heart rhythm.
- Long-standing persistent: This type of atrial fibrillation is ongoing and lasts for more than a year.
- Permanent: The irregular heart rhythm cannot be restored in this type of atrial fibrillation. Medications are required to keep the heart rate under control and to prevent blood clots.
WHAT ARE THE CAUSES OF ATRIAL FIBRILATION?
Understanding the causes of A-fib may be aided by understanding how the heart normally beats.
The typical heart has four chambers: two upper chambers (atria) and two lower chambers (ventricles) (ventricles). The sinus node is a group of cells located in the upper right chamber of the heart (right atrium). The sinus node is the natural pacemaker of the heart. It generates the signal that initiates each heartbeat.
In a regular heartbeat:
- The signal is transmitted from the sinus node to the two upper heart chambers (atria).
- The signal travels through the atrioventricular (AV) node, which connects the upper and lower chambers.
- The signal's movement causes your heart to squeeze (contract), causing blood to flow to your heart and body.
The signals in the upper chambers of the heart are chaotic in atrial fibrillation. As a result, the upper chambers begin to tremble (quiver). The AV node is then bombarded with signals attempting to reach the lower heart chambers (ventricles). This results in a rapid and irregular heartbeat.
In atrial fibrillation, the heart rate can range from 100 to 175 beats per minute. A normal heart rate is 60 to 100 beats per minute.
Atrial fibrillation causes
The most common cause of atrial fibrillation is structural heart problems. Atrial fibrillation can be caused by a variety of factors, including:
- Coronary artery disease (CAD)
- Heart attack
- Being born with a heart defect (congenital heart defect)
- Heart valve issues
- Hypertension
- A problem with the natural pacemaker of the heart (sick sinus syndrome)
- Sleep apnea
- Thyroid disease, such as hyperthyroidism (overactive thyroid), and other metabolic imbalances
- Stimulants, such as certain medications, caffeine, tobacco, and alcohol, are commonly used.
- Viral infections
- Lung diseases
- Surgery, pneumonia, or other illnesses, that can cause physical stress.
- Heart surgery in the past
Some people with atrial fibrillation have no known heart problems or damage to their hearts.
WHAT ARE THE RISK FACTORS OF ATRIAL FIBRILATION?
The following factors can increase the risk of atrial fibrillation (A-fib):
- Age: The older a person gets, the more likely it is that they will develop atrial fibrillation.
- Heart disease: Anyone with a history of heart disease, such as heart valve problems, congenital heart disease, congestive heart failure, coronary artery disease, or a history of a heart attack or heart surgery, is at a higher risk of developing atrial fibrillation.
- Hypertension (high blood pressure): High blood pressure, particularly if it is not well controlled through lifestyle changes or medications, can increase the risk of atrial fibrillation.
- Thyroid disease: Thyroid issues can cause heart rhythm problems (arrhythmias), including atrial fibrillation, in some people.
- Other chronic health issues: People who have diabetes, metabolic syndrome, chronic kidney disease, lung disease, or sleep apnea are more likely to develop atrial fibrillation.
- Alcohol consumption: Drinking alcohol can cause an episode of atrial fibrillation in some people. Binge drinking raises the risk even more.
- Obesity: Obese people are at a higher risk of developing atrial fibrillation.
- Family history: Some families are predisposed to atrial fibrillation.
WHAT ARE THE COMPLICATIONS OF ATRIAL FIBRILATION?
Blood clots are a potentially fatal complication of atrial fibrillation.
The chaotic heart rhythm of atrial fibrillation can cause blood to collect in the upper chambers of the heart (atria) and form clots. If a blood clot in the left upper chamber (left atrium) of the heart escapes and travels to the brain, it can cause a stroke.
As you get older, your chances of having a stroke from atrial fibrillation increase. Other health conditions that may increase your risk of having a stroke as a result of A-fib include:
- Hypertension
- Diabetes
- Heart failure
- Some valvular heart disease
Blood thinners are commonly prescribed to people with atrial fibrillation to prevent blood clots and strokes.
HOW IS ATRIAL FIBRILATION DIAGNOSED?
Some people are oblivious to the fact that they have atrial fibrillation (A-fib). A-fib can be detected when a doctor uses a stethoscope to listen to the heart during a physical exam for another reason.
A doctor may order a battery of tests to rule out other conditions that can cause similar symptoms to A-fib. Among the possible tests are:
- Electrocardiogram (ECG or EKG): The electrical activity of the heart is measured using this quick and painless test. Sticky patches (electrodes) are applied to the chest, as well as the arms and legs on occasion. The electrodes are linked by wires to a computer, which displays the test results. An ECG can reveal whether the heart is beating too quickly, too slowly, or not at all. The primary test for diagnosing atrial fibrillation is an ECG.
- Event recorder: This device is similar to a Holter monitor, but it only records for a few minutes at a time at specific times. It is typically worn for 30 days, which is longer than a Holter monitor. When you experience symptoms, you usually press a button. When an irregular heart rhythm is detected, some devices begin recording automatically.
- Echocardiogram: This noninvasive test creates images of the heart's size, structure, and motion using sound waves.
- Blood tests: These aid a doctor in ruling out thyroid issues or detecting other substances in the blood that may cause A-fib.
- Holter monitor: During normal daily activities, this small, portable ECG device is carried in a pocket or worn on a belt or shoulder strap. It continuously records the heart's activity for 24 hours or longer.
- Stress test: Stress testing, also known as exercise testing, involves running heart tests while exercising on a treadmill or stationary bike.
- Chest X-ray: X-ray images assist doctors in determining the condition of the lungs and heart.
HOW IS ATRIAL FIBRILATION TREATED?
Treatment for atrial fibrillation is determined by how long you've had the condition, your symptoms, and the underlying cause of the irregular heartbeat. The treatment's objectives are as follows:
- Reset the heart rhythm
- Control your heart rate.
- Prevent blood clots from forming, which can lead to a stroke.
Treatment for atrial fibrillation may include:
- Medications
- Therapy to reset the heart rhythm (cardioversion)
- Catheter procedures or surgery
You and your doctors will decide on the best treatment option for you. It's critical to stick to your atrial fibrillation treatment plan. If A-fib is not properly managed, it can lead to other complications such as strokes and heart failure.
Medications
Medication may be prescribed to control how fast your heart beats and restore it to a normal rate. Prescription medications are also given to prevent blood clots, which are a dangerous complication of A-fib.
Among the medications used to treat atrial fibrillation are:
- Beta blockers: These medications can help slow the heart rate both at rest and during physical activity.
- Calcium channel blockers: These medications regulate the heart rate, but they should be avoided by people who have heart failure or low blood pressure.
- Digoxin: At rest, this medication may control the heart rate, but not so well during activity. The majority of people require additional or alternate medications, such as calcium channel blockers or beta blockers.
- Anti-arrhythmic medications: These medications are used to keep the heart rhythm normal, not just to control the heart rate. Anti-arrhythmics are used with caution because they have more side effects than drugs that control the heart rate.
- Blood thinning medications: A blood-thinning medication may be prescribed by a doctor to reduce the risk of stroke or damage to other organs caused by blood clots (anticoagulant). Warfarin (Jantoven), apixaban (Eliquis), dabigatran (Pradaxa), edoxaban (Savaysa), and rivaroxaban are all blood thinners (Xarelto). If you take warfarin, you will need to have blood tests on a regular basis to monitor the drug's effects.
Cardioversion therapy
If the A-fib symptoms are bothersome, or if this is the first episode of A-fib, a doctor may try to reset the heart rhythm (sinus rhythm) with a procedure called cardioversion.
Cardioversion can be accomplished in two ways:
- Electrical cardioversion: This method of resetting the heart rhythm involves administering electric shocks to the heart via paddles or patches (electrodes) worn on the chest.
- Drug cardioversion: To reset the heart rhythm, medications are administered intravenously or orally.
Cardioversion is typically performed as a scheduled procedure in a hospital, but it may be performed in an emergency. Warfarin (Jantoven) or another blood thinner may be given a few weeks before the procedure to reduce the risk of blood clots and strokes.
Anti-arrhythmic medications may be prescribed indefinitely after electrical cardioversion to help prevent future episodes of atrial fibrillation. Even with medication, another episode of atrial fibrillation is possible.
Catheter procedures or surgery
If medications or other therapies do not improve A-fib, a doctor may recommend a procedure known as cardiac ablation. For some patients, ablation is the first line of treatment.
Cardiac ablation creates scars in your heart using heat (radiofrequency energy) or extreme cold (cryoablation) to block abnormal electrical signals and restore a normal heartbeat. A flexible tube (catheter) is inserted by a doctor through a blood vessel, usually in your groin, and into your heart. It is possible to use more than one catheter. The cold or heat energy is applied by sensors on the catheter's tip.
Ablation with a scalpel is used less frequently during open-heart surgery.
There are various kinds of cardiac ablation. The type of treatment used to treat atrial fibrillation is determined by your specific symptoms, overall health, and whether you are undergoing another heart surgery.
Some of the cardiac ablation procedures that may be used to treat atrial fibrillation include:
- Atrioventricular (AV) node ablation: The electrical signaling connection is destroyed by applying heat or cold energy to the heart tissue at the AV node. A pacemaker is required for life after AV node ablation.
- Maze procedure: A doctor creates a pattern of scar tissue (the maze) in the upper chambers of the heart using heat or cold energy or a scalpel. The maze interferes with the stray heart signals that cause atrial fibrillation because scar tissue does not send electrical signals.
If the maze pattern is created with a scalpel, open-heart surgery is required. This is referred to as the surgical maze procedure. It is the preferred method of treating atrial fibrillation in patients who require additional heart surgery, such as coronary artery bypass surgery or heart valve repair.
After cardiac ablation, atrial fibrillation may reoccur. If this occurs, another cardiac ablation or another type of heart treatment may be advised. To prevent strokes after cardiac ablation, blood thinners may be required for the rest of one's life.
If a person with A-fib is unable to take blood-thinning medications, a doctor may recommend a catheter procedure to seal a small sac (appendage) in the left upper heart chamber, which is where the majority of A-fib-related clots form. This is known as left atrial appendage closure. A closure device is gently guided into the sac via a catheter. The catheter is removed once the device is in place. The device is left in place indefinitely. Some people who are already undergoing heart surgery may benefit from surgery to close the left atrial appendage.